Editorial standards

Methodology & sources

VoltTally publishes electrical and home-energy calculators for planning. We show the inputs, the method, the data age, and the safety limits so the result is useful without pretending to be a permit drawing, code ruling, or contractor quote.

Last reviewed: .

How we build calculator pages

We separate code math from page copy

Calculator engines run from explicit formulas and data tables. Page copy explains the result, but the number comes from the same engine used by the UI and generated pages.

We label safety limits

Electrical results are planning estimates. Local code, equipment labels, conductor insulation, installation method, temperature, and the AHJ can change the final requirement.

We prefer inspectable assumptions

Voltage-drop, ampacity, EV charger, heat pump, and running-cost pages show the inputs and assumptions that drive the result instead of hiding the method.

We keep ordinary inputs local

The public calculators run in the browser. You do not need an account, and normal calculator inputs are not uploaded to our servers.

Tool-by-tool source notes

Tool Source basis Known limits
Voltage drop Conductor resistance tables and standard voltage-drop formulas. Does not replace conductor sizing under local code; verify insulation, conduit fill, temperature correction, and AHJ requirements.
Wire size Ampacity reference data and common branch-circuit planning scenarios. The final wire size depends on breaker type, wire material, insulation rating, ambient conditions, and installation method.
EV charger cost Indicative hardware, labor, and panel-work cost ranges. Actual quotes vary by region, panel capacity, permit rules, trenching, wall finish, and installer availability.
Electricity running cost Appliance wattage presets and user-entered electricity rates. Real usage depends on duty cycle, thermostat settings, weather, age of equipment, and utility tariff structure.
Heat pump cost Indicative system, installation, and running-cost assumptions. Load calculation, climate zone, ductwork, rebates, and installer quote details can change the result.

Corrections

Send corrections to [email protected]. Include the page URL, the expected value, and the source you are referencing.

FAQ

Can I use VoltTally instead of a licensed electrician?

No. VoltTally provides planning estimates only. Confirm electrical work with the current code, your local authority, and a licensed professional.

How do I report a stale or unsafe assumption?

Send the page URL, the value or rule in question, and a source link from a code reference, manufacturer document, utility, or authority.