Home / AC Ampere Calculator
Electrical · MCB / breaker

AC Ampere & Breaker Size Calculator

A 1.5 ton 5-star split AC draws about 4.5 A on a 230 V Indian supply; a 3-ton US condenser draws roughly 13 A at 240 V. Use this to pick the MCB / breaker and confirm you need a dedicated circuit.

Inputs

Running current shown; compressor inrush is 3–6× for non-inverter units, which the breaker curve must tolerate. Wiring decisions belong to a licensed electrician.

Reading the numbers like an electrician

The amps shown are running current at the selected efficiency — a 5★ inverter draws roughly 35% less than a 3★ unit of the same tonnage, which is why efficiency matters to wiring, not just to bills. Breakers are sized at ≥125% of running current per standard practice, and non-inverter compressors pull a 3–6× inrush at start that the breaker's trip curve absorbs; inverters soft-start and largely sidestep it. Three things this calculator deliberately doesn't decide: wire gauge (length-dependent — the run from panel to condenser changes the answer, our sister voltage drop calculator covers it), shared-circuit feasibility (ACs get dedicated circuits, full stop), and whether your panel as a whole can take the load — that's the selector below, and the panel capacity guide in detail.

Result
AMPS
Power draw
Suggested MCB / breaker
CircuitDedicated circuit required
Cross-check long cable runs with our sister tool voltdropcalc.com to keep voltage drop under 3%.