The NEC wire sizing calculator that works where you work -- even with no signal.
WireCalc gives electricians, contractors, and apprentices instant access to NEC 2023
wire sizing, voltage drop calculations, and conduit fill tables. No internet required.
No subscription. Just accurate answers on the job site.
STOP OVERSIZING WIRE. STOP GUESSING.
Enter your load and run length. Get the correct wire gauge per NEC 310.16 in seconds.
Check voltage drop. Verify conduit fill. Solve Ohm's law. All based on NEC 2023
(NFPA 70) tables.
FEATURES:
- Wire size calculator -- sizes by both ampacity AND voltage drop per NEC
- Full NEC Table 310.16 ampacity reference (interactive, searchable)
- Voltage drop calculator (single-phase and three-phase)
- Conduit fill calculator with NEC Chapter 9 data (EMT, IMC, RMC, PVC)
- Ohm's law calculator (V, A, Ohm, W -- enter any two, get all four)
- Copper and aluminum conductor support
- 60°C, 75°C, and 90°C temperature ratings
- THHN, THWN, XHHW, TW, THW insulation types
- Pass/fail indicators with NEC-compliant thresholds
WHY ELECTRICIANS CHOOSE WIRECALC:
- Works 100% offline -- designed for job sites with zero signal
- No subscriptions, no ads, no account required
- One-time purchase -- yours forever
- NEC 2023 compliant tables and calculations
- Large text and tap targets -- usable with work gloves
Based on NEC 2023 (NFPA 70).
Note: This app is a calculation tool and reference guide. It does not replace
professional judgment or code compliance verification. Always verify calculations
and consult local codes and amendments.