How Many Amps Does an Appliance Draw?

Watts, volts, and amps: the one formula

Power, voltage, and current are tied together by one simple relationship: watts equal volts times amps. Rearranged, amps equal watts divided by volts. Manufacturers almost always print the power in watts because it is voltage-independent, but the socket, breaker, and wire care about current. So the everyday task is to turn a watt rating into an amp figure by dividing by the voltage your country supplies.

The voltage in that division is not a detail — it flips the answer. Because North America runs household outlets at about 120 volts and most of Europe at about 230 volts, the identical appliance draws almost twice the current on the lower voltage. A 1,500-watt kettle is a 12.5-amp load at 120 volts but only a 6.5-amp load at 230 volts. That single fact explains why North American kitchens need more dedicated circuits than European ones for the same set of appliances.

Start-up surge and the power factor catch

The running current is only half the story for anything with a motor or compressor. Fridges, air conditioners, pumps, and power tools pull a brief inrush current several times their running amps at the instant they start, as the motor overcomes inertia. It lasts a fraction of a second, but it is why a fridge can flicker the lights and why breakers and generators must be sized for the surge, not just the steady draw. A 5-amp running motor might spike to 25 or 30 amps for a heartbeat.

There is a second subtlety with motors and electronics: the power factor. Some devices draw more current than a simple watts-over-volts sum suggests, because voltage and current fall out of step. For resistive loads like heaters, kettles, and incandescent bulbs the power factor is essentially one and the simple formula is spot on. For motors, LED drivers, and switching supplies, a nameplate amp figure is more reliable than back-calculating from watts. When accuracy matters, trust the current stamped on the plate.

Why the amp figure matters at home

Knowing an appliance's current turns a shrug into a decision. A circuit is protected by a breaker of a fixed rating — 16 amps is common in Europe, 15 or 20 amps in North America — and everything on that circuit shares the budget. Plug a 12.5-amp heater into a circuit already carrying an 8-amp load and you are over a 20-amp limit, so the breaker trips or, worse, a poorly protected circuit overheats. Adding up amps before you plug in is how you avoid nuisance trips and unsafe overloads.

The same figure sizes a generator and chooses a wire. A backup generator must cover the running amps of everything you want on at once, plus the biggest start-up surge, or it stalls when the fridge kicks in. And the current, matched to the run length, decides the wire gauge that carries it safely. So the humble amps = watts ÷ volts sum quietly underpins circuit planning, generator sizing, and cable choice — three tools that all begin with the number this calculator gives you.

Frequently asked questions

How do I convert watts to amps?

Divide the watts by the supply voltage. At 120 volts, 1,200 watts is 1,200 ÷ 120 = 10 amps; at 230 volts, the same 1,200 watts is 1,200 ÷ 230 = 5.2 amps. Because the voltage differs by region, always divide by your own supply voltage.

How many amps does a fridge use?

A typical household fridge runs at roughly 1 to 2 amps while its compressor cycles, but it briefly surges to several times that at start-up. Read the nameplate for the exact running current, and remember to allow for the start-up surge when sizing a breaker or generator.

Why do North America and Europe give different amps for the same appliance?

Because amps depend on voltage. North American outlets supply about 120 volts and European ones about 230 volts, so dividing the same wattage by a different voltage gives a different current — roughly half the amps at 230 volts as at 120 volts. The watts are the same; the current is not.

Can I add two appliances on the same circuit?

Only if their combined running amps, plus the biggest start-up surge, stay safely below the breaker rating — a common guideline is under 80% for continuous loads. Add up each device's amps first. Two high-draw items like a heater and a kettle often need separate circuits; when in doubt, ask an electrician.