Refrigerator Compressor Amp Calculator

What circuit does your fridge actually need?

Convert refrigerator wattage to running and starting amps, then size the dedicated circuit. Uses Ohm's law (Amps = Watts ÷ Volts), compressor surge multipliers, and NEC 210.19 continuous-load sizing (125%).

⏱ ~30 sec•Ohm's law + NEC 210.19•Installation & Setup

W ÷ V

Running amps

Ohm's law

3–5×

Surge

Standard compressor

1.75×

Surge

Inverter

125%

Circuit margin

NEC 210.19

STEP 01

Three inputs.
Real circuit spec.

Wattage from the nameplate, voltage from the outlet, compressor type from the spec sheet.

Wattage

Find on the inside-fridge nameplate or spec sheet.

Voltage

Compressor type

Updates live as you type

Running amperage

1.25A

15-amp circuit · 15A breaker · 14 AWG

Starting surge

5.0 A

Required circuit

1.6 A

Under the hood

Ohm's law. NEC sizing.

Running amps = watts ÷ volts. Surge multipliers come from compressor manufacturer ratings; circuit sizing follows NEC 210.19(A) and conductor ampacity from NEC 310.16.

01
Running amps (Ohm's law)
Amps = watts ÷ voltage. A 150W fridge on 120V draws 1.25 amps continuous.
02
Starting surge
Standard compressor: 4× running amps. Inverter: 1.75×. Variable speed: 2×. Brief but high — must not nuisance-trip the breaker.
03
Circuit per NEC 210.19
Required circuit = running amps × 125% safety margin. Round up to the next standard breaker size: 15, 20, 30, or 40A.
04
Wire gauge per NEC 310.16
14 AWG for 15A, 12 AWG for 20A, 10 AWG for 30A, 8 AWG for 40A. Derate for ambient temp and conductor count.

Questions

Frequently asked

Modern household refrigerators run between 1.5 and 6 amps at 120V (roughly 180–725 watts). Starting surge can briefly hit 3–5x that for single-speed compressors. Inverter compressors stay closer to 1.5–2x running amps.