Electric Ref: Wire Size & Fill

About

Type the amps, get the wire size. Pick a conduit, see how many conductors fit. Electric Ref answers the questions electricians ask every day — in three taps, fully offline. SIZE WIRES CORRECTLY - Amps to conductor size with temperature correction, conductor bundling adjustment and termination limits applied automatically - Copper and aluminum, 60/75/90°C insulation - Small-conductor breaker caps built in - Every answer shows WHY — the code articles and factors behind it CONDUIT & BOX FILL - Max conductors for EMT, RMC, IMC, PVC 40/80, ENT, FMC, LFMC and more - THHN, XHHW, TW/THW wire types - Box fill with device, clamp and ground allowances MORE FIELD TOOLS - Voltage drop (DC and AC methods, any power factor, conduit material) - Motor full-load current, conductor and breaker sizing - Equipment grounding and grounding electrode conductor sizes - Transformer currents, Ohm's law wheel REFERENCE CHARTS - Hole saw and knockout sizes (triple-checked) - NEMA plug and receptacle configurations - Motor starter sizes, wire color codes - Burial depths, conduit support spacing, wire properties BUILT FOR THE FIELD - 100% offline — works in basements, new construction, anywhere - Big glove-friendly controls, screen stays awake - No account. Your calculations never leave your phone. ONE-TIME PURCHASE The free version includes the Ohm's law wheel, daily wire sizing and core reference charts. Electric Ref Pro is a single one-time purchase that unlocks every calculator and chart. No subscription. No ads. No feature removals. Ever. Values are based on the National Electrical Code®. Reference only — always verify with your locally adopted code edition and AHJ. NEC is a registered trademark of the National Fire Protection Association, which does not endorse this app.