Watts to Amps

Convert electrical power in watts to current in amps given voltage and power factor. Free, instant, no signup.

Formula: Amps = watts ÷ (volts × power factor)

How to use the Watts to Amps

  1. Enter your values. Fill in the fields with your numbers.
  2. Calculate. Press Calculate to run the watts to amps.
  3. Use the result. Copy the result or try a related tool next.

Why use our Watts to Amps

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About the Watts to Amps

Watts to Amps converts a power figure (watts) into the electric current (amps) a device or circuit will draw, given the voltage it runs at. This is one of the most-searched electrical conversions because nearly every appliance label lists watts, but the numbers that actually matter for safety and wiring (fuses, breakers, cable gauge) are in amps. You cannot go from watts to amps without knowing voltage, because the two units measure different things: watts are the rate of energy use, while amps are the flow of charge. Voltage is the missing link that ties them together.

Reach for this converter whenever you need to know how much current a load pulls. Common cases: checking whether a 1500 W heater overloads a 120 V kitchen circuit (it draws 12.5 A), sizing a fuse or DC breaker for a 12 V camper or RV solar setup, working out if a generator or inverter can run several appliances at once, or planning the wiring for a 240 V dryer or EV charger. It is also handy when comparing the same device on different supplies, since the current changes with voltage even though the wattage stays the same.

The tool applies the standard relationships. For DC and purely resistive AC loads: Amps = Watts / Volts. For single-phase AC with a reactive load: Amps = Watts / (Volts x Power Factor). For three-phase the denominator includes a phase factor of 1.732 (line-to-line) or 3 (line-to-neutral). Power factor matters because watts measure real power, while the current is set by apparent power (volt-amps). Resistive loads such as heaters and incandescent bulbs sit at a power factor of 1.0; motors, LED drivers and mixed equipment typically run 0.7 to 0.95, so the same wattage pulls more current than the simple formula suggests.

Every calculation runs entirely in your browser using these formulas. Nothing you type, no wattage, voltage, or power factor, is sent to a server, stored, or logged. The results are mathematically exact for the inputs you provide, but real circuits can vary: actual mains voltage drifts, motor inrush current briefly spikes well above the running figure, and nameplate watts may be peak rather than continuous. Treat the output as an accurate planning figure, and for permanent wiring, fuse, or breaker decisions, confirm against your equipment's data plate and local electrical code, or consult a qualified electrician.

Frequently asked questions

How do I convert watts to amps?

Divide the power in watts by the voltage. For example, 1200 watts at 120 volts is 1200 / 120 = 10 amps. For AC loads with a power factor below 1, divide again by the power factor.

Can I convert watts to amps without knowing the voltage?

No. Watts and amps measure different quantities, and voltage is the link between them. You must supply the voltage of the supply or device, such as 12 V, 120 V, or 240 V, to get a current figure.

Why does the same wattage draw different amps at 12V, 120V, and 240V?

Because amps equal watts divided by volts, a higher voltage means lower current for the same power. A 1200 W load draws 100 A at 12 V, 10 A at 120 V, and just 5 A at 240 V, which is why high-power devices use higher voltages to keep current and wire size manageable.

What power factor should I use?

Use 1.0 for resistive loads like heaters, kettles, and incandescent bulbs. Use about 0.8 to 0.9 for motors and many appliances, and 0.85 to 0.95 for LED drivers and mixed commercial equipment. DC circuits do not use a power factor.

Is the amp result safe to use for sizing a fuse or breaker?

It gives the running current, but protective devices are usually sized above that. A common rule for continuous DC loads is 125 percent of the calculated current rounded up to the next standard size, and motors draw a higher inrush current at startup. Always check your equipment rating and local code.

From our blog

Cooking Conversions Made Simple: Cups, Grams, and Why Your Scale Wins

By the Super Simple Digital Tools Team · Updated June 2026

Almost every cook hits the same wall eventually: a recipe you want to make is written in units your kitchen does not speak. Maybe it is an American cake recipe listing cups and sticks of butter, or a European one in grams and millilitres. The good news is that conversion is mostly arithmetic, and once you understand which numbers are fixed and which depend on the ingredient, you can adapt any recipe with confidence.

Start with the volume measures, because these never change. A teaspoon is a third of a tablespoon, a tablespoon is a sixteenth of a US cup, and a US cup is just under 237 millilitres. These ratios hold no matter what is being measured, whether it is water, oil or vanilla extract. So if a recipe wants a quarter cup of milk and you only have measuring spoons, you can confidently use four tablespoons. This is the easy, predictable half of cooking conversion.

The trickier half is moving between volume and weight. Grams and ounces measure mass, and mass depends on how densely an ingredient packs into a cup. This is why a single cup measurement can equal wildly different weights: roughly 120 grams for fluffy all-purpose flour but around 200 grams for granulated sugar, which packs tightly. A converter that ignores the ingredient and uses one fixed gram-per-cup figure will be wrong for almost everything, which is why selecting the actual ingredient matters so much.

Be aware that the cup itself is not universal. The US cup is about 240 millilitres, the metric cup used across Australia and New Zealand is 250 millilitres, and the historic UK imperial cup was larger still at about 284 millilitres. For a soup or a stew this rarely matters. For a delicate sponge or a bread dough, where the balance of flour to liquid is critical, using the wrong cup standard can leave you with a batter that is too wet or a cake that refuses to rise.

If you take one thing away, let it be this: weighing beats measuring by volume. Professional bakers work in grams precisely because a scale removes the guesswork of how firmly you packed the cup or whether the flour had settled. A converter is perfect for translating a recipe quickly and for everyday cooking, but when accuracy counts, convert the volume amounts to grams once, then weigh them. Your results will be far more consistent from one batch to the next.

  • Always choose the specific ingredient before converting cups to grams; flour, sugar and butter all weigh different amounts per cup.
  • Remember the core spoon ratios: 3 teaspoons make a tablespoon and 16 tablespoons make a US cup, so you can swap between them without a tool.
  • Check whether a recipe uses US (about 240 ml) or metric (250 ml) cups before baking, since the difference can affect rise and texture.
  • For the most reliable baking, convert your volume measurements to grams once and weigh the ingredients on a digital scale instead of scooping.

Read the full guide →

Tool by the Super Simple Digital Tools Team. Reviewed by our editorial team. Free to use, no signup required.

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