Free Solar Business Tools
Calculators Built for Solar Sales Orgs & Installers
Eighteen free tools for the decisions a fulfillment business actually makes: working capital, dealer margins and proceeds by funding product, commission and headcount planning, funnel and fallout economics, adder pricing, subcontract rates, and permit, PTO, and funding readiness. No signup required.
Backwater Valve Requirement Checker
Whether a basement needs a backwater valve is decided by an elevation that is not on the property: the cover of the next manhole upstream in the public sewer, which is where a surcharged sewer relieves itself and therefore the ceiling on how high a backup can reach. The tool asks separately which reference you measured against, because street level at the house and the top of the basement slab are both wrong and both produce a confident number. It compares each fixture's flood level rim individually rather than returning one verdict for the storey — a floor drain and a laundry tub in the same basement can fall on opposite sides of the line. Where the valve goes in the building drain and fixtures from above that elevation drain through it, it applies the normally open requirement, and the exception permitting the normally closed type only where the building is existing. Plus access to the working parts, the three material standards, and the junction cleanout and its 18 inch clearance. No fixture verdict is issued at all until the governing datum has been supplied.
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Washing Machine Standpipe Checker
Check a laundry standpipe against four requirements that arrive from three different parts of the code and are reported separately. The height against a window of 18 to 42 inches measured from the trap weir rather than the floor — the tool collects the floor measurement separately so it can name the case where the wrong datum would have passed. Whether a laundry tray drains into the same standpipe, which moves the minimum to 30 inches and adds a condition that is not a dimension at all: the standpipe must also clear the tray's flood level rim. The 2 inch trap minimum, which is larger than the 1.5 inch trap serving the sink beside it. And the developed length from the trap weir to the vent fitting, applied against the trap size you actually have rather than the one required.
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Garage Appliance Installation Checker
Two requirements apply to a water heater, furnace or other appliance installed in a garage, and meeting one does nothing for the other. This checks both independently. Elevation: whether the appliance has an ignition source at all, whether either exception removes the requirement — a flammable-vapor-ignition-resistant listing, or a separate enclosed space entered only from outside the garage and drawing its combustion air from outside it — and where the ignition source actually sits relative to 18 inches. It collects the platform height separately so it can name the case where the platform clears 18 inches and the ignition source does not, which is how this is most often built wrong. Impact protection: whether the location is subject to vehicle damage, whether barriers are installed, and whether the code official has accepted the detail. It returns no barrier dimension, because the code assigns none.
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Deck Ledger Connection Checker
Check a deck ledger against the prescriptive requirements, line by line. It runs the disqualifying conditions first — a ledger on stone or masonry veneer, a band joist that does not bear fully on the structure, or a beam landing on the ledger — and withholds the spacing lookup rather than returning a number that does not govern. Then the on-centre fastener spacing for the joist span, fastener and sheathing thickness; the two staggered rows with their row spacing and top, bottom and end distances; the two different drill diameters a half-inch lag screw needs plus tip penetration and full-body diameter; and the lateral load connection, which is a separate requirement that the fastener schedule does not satisfy.
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Egress Window Compliance Checker
Check a basement or bedroom window against the emergency escape and rescue requirements, line by line: net clear opening width against 20 inches, clear height against 24 inches, and clear area against 5.7 square feet — or 5 square feet only where the sill is within 44 inches above or below the outside ground, which the tool derives from a measurement rather than asking you to classify it. Plus the 44-inch maximum from the finished floor to the bottom of the clear opening, and where the opening is below grade, the area well: projection, width, 9 square feet of area, whether the well lets the sash open, and a vertical depth computed from both the below-grade and above-grade parts so the ladder trigger is not missed.
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Electrical Working Clearance Checker
Check a proposed mounting location for inverters, disconnects and panelboards: clear depth in front, clear width against 30 inches or the equipment width whichever is greater, headroom against 78 inches or the equipment height whichever is greater, whether the covers swing to 90 degrees, and whether the dedicated space above a panelboard is clear of pipes and ducts. Measurements are yours; a blank is reported as not measured.
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Critical Load Panel Planner
Which circuits a home battery will actually keep running — the running total against the inverter's continuous rating, the largest motor starting while the rest runs against its surge rating, daily energy against the battery's usable capacity, and the list against the spaces in the panel. Figures are entered from your own datasheets; a blank is reported as blank.
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Amps to Watts Calculator
Amps to watts for DC, single-phase and three-phase circuits, with power factor applied — and, from a breaker rating, what the circuit can actually carry: the full rating, the 80 percent continuous figure, and the NEC 210.23(A) limits on a single plug-in appliance and on fastened-in-place equipment.
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Volts to Watts Calculator
Watts from volts and current (with power factor on AC, and √3 on three-phase), from volts and a heating element's resistance, or from an appliance's rating at a different voltage — the 240 V element on a 208 V apartment service that delivers about 75 percent of its rating.
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kW to Amps Calculator
Current from a kW rating on DC, single-phase or three-phase, with power factor applied, the kVA shown, and a motor's kW treated as the shaft output it is — so the current is not understated by the efficiency. States that motor circuits are sized from the NEC 430 tables, not this figure.
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kVA to kW Calculator
Real power from a kVA rating with power factor applied — and a nameplate that already lists both figures checked for consistency, without treating conversion as generator sizing.
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kW to kVA Calculator
Apparent power from a kW rating with power factor applied — and a motor's shaft kW treated as output, so efficiency is divided back in before the conversion.
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kW to HP Calculator
Horsepower from kilowatts in all three horsepowers — mechanical, electrical and metric — with a motor's electrical input kW multiplied by efficiency before it converts, so shaft output is not overstated.
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HP to kW Calculator
Shaft kilowatts from horsepower, plus what the motor draws once efficiency is applied — with the service factor read as an overload allowance, not the rating.
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HP to Watts Calculator
Watts from horsepower (hp × 746) for fractional and small motors, with a volts × amps check against the NEC Table 430.248 full-load current that shows why a small motor draws far more than its shaft watts.
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kW to kWh Calculator
Kilowatt-hours from kilowatts and time (kWh = kW × hours), for a steady load or one that changes in steps — with the peak kW and average kW kept next to the energy as the separate limit it is.
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kWh to kW Calculator
Average kilowatts from kilowatt-hours and time (kW = kWh ÷ hours) for a bill, a battery discharge or a charging session — labelled as the average it is, with an optional load factor against a peak you supply.
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kW to Watts Calculator
Watts from kilowatts (kW × 1,000) with common nameplate sizes, plus an optional kVA × power factor path when the plate shows apparent power instead of real power.
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Watts to kW Calculator
Kilowatts from watts (W ÷ 1,000) with common label presets, plus an optional VA × power factor path when the plate shows volt-amps instead of watts.
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Ohm's Law Calculator
Any two of volts, amps, ohms and watts give the other two — in milliamps and kilohms too — with the limit stated: the formulas describe DC and resistive loads, and an ohmmeter reading across a motor winding does not predict its running current.
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Milliamps to Amps Calculator
Amps from milliamps (mA ÷ 1,000), with watts at a stated voltage, a mAh mode that keeps battery capacity separate from current, and the figure read against the 4–6 mA Class A GFCI trip range.
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Amps to Milliamps Calculator
Milliamps from amps (A × 1,000), with watts at a stated voltage and the result read against USB port limits and the 4–6 mA Class A GFCI trip range — where the small decimals that get misread actually matter.
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mAh to Wh Calculator
Watt-hours from milliamp-hours at the voltage the rating is stated at (and back), how many charges a power bank really gives once losses are counted, and where the result sits against the FAA 100 Wh line.
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Watt Hours to Amp Hours Calculator
Amp-hours from watt-hours at a stated battery voltage — with depth of discharge and inverter efficiency when the Wh figure is an AC load.
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Amp Hours to Watt Hours Calculator
Watt-hours from amp-hours at a stated battery voltage — nameplate and usable energy, with optional inverter efficiency for an AC figure.
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Watts to kWh Calculator
Kilowatt-hours from a wattage or from amps and volts — with power factor on AC, a duty cycle for loads that cycle, daily and monthly projections, and an optional utility rate. Watts alone never give a kWh figure.
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Watts to Volts Calculator
Volts from watts and current (with power factor on AC, and √3 on three-phase) or from watts and a heating element's resistance — with the answer read against 120, 208, 240, 277 and 480 V and the ±5 percent ANSI C84.1 Range A band, so figures that do not belong together are flagged rather than converted.
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Amps to kW Calculator
kW from current on DC, single-phase or three-phase, with power factor applied and the kVA shown — and, from a breaker rating, the 80 percent continuous-load figure, or from a motor's current, the shaft output its nameplate would show.
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VA to Amps Calculator
Current from a volt-ampere rating for DC, single-phase or three-phase equipment — no power factor, because VA already is apparent power — and a UPS label that prints both VA and watts checked, so the current is not read from the smaller figure.
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Amps to kVA Calculator
Apparent power from a current and voltage, single-phase or three-phase — with a breaker or service rating kept separate from an actual load, the line-to-neutral voltage mistake flagged, and common transformer ratings shown as reference points, not a selection.
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kVA to Amps Calculator
Full-load current from a transformer or generator kVA rating, single-phase or three-phase — with no power factor, because kVA does not take one, and the two voltage entries that produce a confident wrong answer (line-to-neutral into the three-phase formula, 120 V for a 120/240 V secondary) flagged with the corrected figure.
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Watts to Amps Calculator
Watts to amps for DC, single-phase and three-phase circuits, with power factor applied rather than assumed — then the 125 percent continuous-load factor in NEC 210.19(A)(1) and 210.20(A) and the smallest standard overcurrent device in NEC 240.6(A). Declines to name a wire size, because the inputs for that are not on the page.
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Dryer Vent Length Calculator
Spend the 35-foot dryer duct allowance elbow by elbow — 5 feet per 90-degree bend, 2 feet 6 inches per 45 — and check the termination, the backdraft damper and the transition duct against IRC Section M1502 before the wall closes.
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HVAC Condensate Overflow Protection Checker
Whether a cooling coil needs a secondary drain, an auxiliary pan or a UL 508 float switch — the consequence test in IRC M1411.3.1, the four alternative methods, the pan specification, and the primary-drain requirements that apply either way.
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HVAC Replacement Quote Checker
A furnace, air conditioner or heat pump proposal against twelve things it should state in writing — equipment model numbers, the AHRI reference for the combination, the permit, the refrigerant, and documented startup measurements.
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Home Battery Siting Checker
The room a homeowner has in mind is often the one the code rules out. Test prohibited locations first under IRC R328, then the four permitted ones, the 20 kWh unit cap, location aggregates, and readiness items.
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Home Improvement Contract Review Checklist
Residential PV solar is a home improvement in most states, so the homeowner agreement is governed by a statute with a mandatory content list. Read yours against 31 terms and formalities.
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Solar Dealer Program Scorecard
Score a dealer program across 33 commercial terms — margin, financing breadth, install capacity in your own metros, accountability, money timing, territory and exit — marking each one written, stated only, or unaddressed.
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Rapid Shutdown Compliance Checker
Most NEC 690.12 failures are not equipment failures. Establish the enforced edition, test whether the equipment route can meet the inside-boundary limit, then work the five readiness items an inspection actually turns on.
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Roof Recover Eligibility Checker
A second layer is a code question before it is a price question. Answer the three prohibitions in IRC R908.3.1.1 and see whether a recover is available at all, or whether the roof is a tear-off.
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Usable Roof Area Calculator
Fire setbacks and access pathways come off before a single module is placed. See what is left of a roof plane, and what the clear areas cost in modules.
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Solar Backfeed Capacity Calculator
Work out how much solar a main panel can accept from its busbar rating, main breaker and feed position, and see the usual exits when it does not fit.
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Permit Revision Decision Tool
A field change moved the installation away from the approved set. Decide whether it is an as-built note, a permit revision or a separate application.
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AHJ Requirements Checklist
Capture what an authority having jurisdiction actually requires before a plan set is drawn: adopted code editions, local amendments, submittal mechanics, stamp policy, revision handling and inspection sequence.
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Solar Site Survey Checklist
Score what a site survey actually captured across electrical service, structure, shading, routing, access and account data, with the items that force a redesign flagged separately.
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Direct Pay Working Capital Calculator
See exactly how much capital your sales org ties up in materials every month, and what $0 upfront through Direct Pay frees up.
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Solar Dealer Margin Calculator
Enter system price, install cost, and dealer fee to see your gross margin per deal, monthly revenue, and annual earnings projection.
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Solar Project Timeline Estimator
Estimate weeks from signed deal to PTO by state, permit jurisdiction, HOA status, and financing type, with a milestone breakdown.
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Solar Financing Type Selector
Answer 4 questions about a homeowner and get a recommended financing product (TPO, loan, or sell-on-paper) with the right lenders from Seamless Home's network.
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Installer Revenue & Capacity Calculator
Enter crew count, installs per week, and current utilization to see your monthly revenue, full-capacity potential, and how much deal flow you could absorb.
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In-House vs. Outsourced Fulfillment Calculator
Price the fulfillment stack both ways, fixed overhead plus materials capital against a flat per-deal fee, and find the installed volume where the answer flips.
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Solar Sales Commission Calculator
Model the same deal under all three structures, per-watt redline, % of gross margin, and flat per deal, and see what it pays the rep and what it leaves the org.
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Solar Permit Package Checklist
Score a project's permit readiness across intake, drawings, calculations, and submission, with blocking items separated from the ones that just draw a correction notice.
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Final Inspection Readiness Checklist
Walk a finished installation the way the inspector will. Documents, conformance, conductors, bonding, labels and clearance, with the high-frequency corrections flagged.
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PTO & Interconnection Checklist
Two approval chains gate Permission to Operate, the utility's and the jurisdiction's. Score where a project stands and find the unowned handoff that is holding it.
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Funding Packet Checklist
Funding gets rejected for paperwork, not bad deals. Check credit validity, executed docs, install evidence, and final-draw items, gated by the draw you're claiming.
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Solar Sales Funnel Calculator
Doors to installs with every stage rate exposed: plus which stage is worth the most per point, and where you're actually leaking the most volume.
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Deal Fallout Cost Calculator
A cancellation isn't one number. Price what a dead deal costs at each stage, and see the effective margin per install once fallout is spread across the survivors.
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Solar Adder Margin Calculator
Panel upgrades, reroofs, trenching, batteries, critter guard. Price each against your real cost and find which adders make money and which you're giving away.
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TPO vs Loan vs Cash, Dealer Proceeds
Same system, three funding paths, three different numbers landing in your account. Compare proceeds after dealer fee, build cost, and commission.
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Solar Rep Ramp & Headcount Planner
Target ÷ installs per rep is the wrong answer. Model ramp, attrition, and the headcount ceiling your hire rate can actually sustain, plus the cash trough.
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Install Subcontract Rate Calculator
Does the per-watt rate work for the crew? Break it into loaded labour, mobilization, overhead, and rework, then see what retention and payment terms really cost.
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Solar Warranty Coverage Checker
One system, seven separate promises, seven counterparties. See which layers are still in term, and which quietly depend on a contractor still being in business.
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HVAC & Roofing Expansion Calculator
You already paid to acquire the customer. Model what a second service is worth at your attach rate, and the rate below which building it in-house doesn't pay.
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Solar Project Takeover Checklist
Assess one stalled project in the order that keeps a takeover economic: the record, the drawings, the built work, the money, the approvals and the homeowner.
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Installer Vetting Scorecard
Six domains decide whether a partner is safe to route volume to: licence and entity, insurance, bonding, capacity, warranty and financial durability. Score all of them.
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Notice to Proceed Readiness Checker
Four gates stand between a signed deal and a scheduled install. Find the specific blocker, deals do not age at this gate for big reasons.
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Project Responsibility Matrix
Assign all 25 project tasks to the sales org, fulfillment partner, installer or homeowner, and surface the handoffs both sides assume the other is handling.
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Solar Cash Conversion Cycle Calculator
The days between paying for a deal and being paid for it. Model the gap across materials, labour and milestone draws, and see what it ties up at your volume.
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Subcontract Agreement Review Checklist
Read an install subcontract against 28 clauses, marking each Covered, Unclear or Silent. Silence is the finding a read-through never records.
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Built for the B2B side of solar
These tools are designed for solar sales organizations, installers, and EPCs, not homeowners. Every calculator maps to a real decision your business faces: how much capital to deploy, which financing product to offer, whether your crews have capacity for more deal flow.
Informational use only, please verify before you rely on it
This applies to every calculator on this page. Each one is a planning aid, not a quote, a credit decision, or a substitute for professional advice.
This tool is provided for general informational and educational purposes only. Its output is an illustrative estimate generated from the values you enter and from general assumptions that will not match every deal, market, lender, or homeowner. It is not tax, legal, accounting, financial, or professional advice, and it is not a quote, an offer, a credit decision, or a guarantee of pricing, approval, timing, savings, or eligibility.
You are solely responsible for independently confirming all information presented here including any figures, rates, fees, margins, timelines, tax treatment, and federal, state, local, or utility incentives, with the applicable lender, authority having jurisdiction, and your own qualified tax, legal, and financial advisors before acting on it, relying on it, or presenting it to a homeowner or any third party. Incentive programs, lender terms, and permitting requirements change frequently and vary by jurisdiction.
Seamless Home is not a tax advisor, law firm, lender, or licensed installing contractor, and makes no representation or warranty as to the accuracy, completeness, or currency of the information produced by this tool. To the fullest extent permitted by law, Seamless Home accepts no liability for any decision made or action taken in reliance on it.
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