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Sauna Heater Electrical Circuit Calculator
Enter the heater and your wiring run. You get the breaker size, copper wire gauge and voltage drop worked to NEC — the exact spec to hand your electrician for the permit, with the wire upsized automatically on a long run.
Licensed electrician required. This is a reference estimate, not an electrical design. Circuit sizing, GFCI/GFPE requirements, and conductor selection must be verified and installed by a licensed electrician to your local code (NEC and any local amendments take precedence).
How it is calculated
- Amps = watts ÷ volts (a 240V, 8 kW heater = 33.3 A).
- Breaker ≥ 125% of load (NEC continuous-load rule), rounded up to a standard size.
- Wire = smallest 75°C copper conductor that carries the breaker, then upsized until single-phase voltage drop over your run is ≤ 3%.
Full methodology & assumptions ›