About SizeBench

SizeBench builds free, fast technical calculators for electricians, solar installers, network techs, boat owners, RVers and DIYers. Each tool answers one practical question, such as what wire size a circuit needs or how many panels will cover a power bill, and shows exactly how the answer was calculated.

How we build our calculators

Every calculator uses published standards (NEC, ABYC, IEC, TIA, IEEE) and standard industry formulas, and each page shows the formula and a worked example so you can check the math yourself. Calculations run entirely in your browser; nothing you type is sent to a server.

Accuracy

Results are estimates. Real-world quantities depend on site conditions, product specifications and installation methods. Confirm quantities with your supplier or contractor before ordering, and follow local building codes.

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