Electrician Calculators
Free NEC-compliant tools for conduit fill, Ohm's Law and wire gauge. Instant results for electricians and DIYers — no signup needed.
Electrical work demands precision. An undersized wire overheats under load; a conduit packed past NEC limits fails inspection and risks a fire. These tools do the reference-table lookups that slow down every job — conduit fill percentages, Ohm's Law permutations, and wire gauge selection — so you can focus on the work itself.
What these tools cover
The conduit fill calculator checks your wire count and AWG sizes against NEC Chapter 9 fill limits (40% for 3+ conductors) for EMT, IMC, and rigid conduit. The Ohm's Law calculator solves for voltage, current, resistance, or power given any two known values — useful for load calculations and troubleshooting. The wire gauge calculator recommends the correct AWG based on current draw, run length, and allowable voltage drop.
NEC compliance notes
These calculators reference the National Electrical Code (NEC). Local jurisdictions sometimes adopt amended versions — always verify against the edition adopted in your area. For permitted work, results from these tools are a starting point for your design; a licensed electrician or inspector has final authority on code compliance.
Found a code table that needs updating? Contact us and we'll correct it promptly.