# How do I convert watts to amps?

Converts watts to amps and back: amps = watts ÷ volts.

- Page: https://www.acalculator.org/convert/watts-to-amps
- JSON spec: https://www.acalculator.org/convert/watts-to-amps.json
- Version: 09b928fb8ce4

## Default answer

Example with the default inputs (Watts (W) 1, Voltage (V) 120): 1 watts = 0.008333 amps.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| value | Watts (W) | The amount in watts. |
| volts | Voltage (V) | 120 V for a US outlet, 230 V in Europe. |
| result | Amps (A) | The same amount in amps. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| value | Watts (W) | The amount in watts. |
| volts | Voltage (V) | 120 V for a US outlet, 230 V in Europe. |
| result | Amps (A) | The amount in amps. |

## Method

amps = watts ÷ volts

## Assumptions

- Exact on the typed decimals: at most 6 decimal places (6 significant digits below 0.0001), rounded half up.

## Worked examples

1. value = 1,200, volts = 120 gives result = 10. Source: NIST SP 811 (2008), Table 3: W = V × A.
2. value = 60, volts = 12 gives result = 5. Source: NIST SP 811 (2008), Table 3: W = V × A.

## FAQ

### How do I convert watts to amps?

Divide watts by volts: amps = watts ÷ volts, because 1 watt is 1 volt × 1 ampere. A 1,200 W heater on a 120 V outlet draws 1,200 ÷ 120 = 10 A.

### How many amps is 1,000 watts?

It depends on the voltage: 8.33 A at 120 V, 4.35 A at 230 V, and 83.3 A at 12 V.

### Why do I need the voltage?

Power is voltage times current. The same watts at a higher voltage need fewer amps, so watts alone do not fix the amps.

### Does this work for AC motors and other AC loads?

It is exact for DC and for AC loads like heaters and incandescent bulbs, whose power factor is 1. For a motor or a power supply, divide by the power factor as well: amps = watts ÷ (volts × power factor). For three-phase power, also divide by √3.

### How many watts can a 15 amp circuit carry?

15 × 120 = 1,800 W at 120 V. Electricians plan continuous loads at no more than 80% of that, 1,440 W.

## Sources

- NIST SP 811 (2008), Guide for the Use of the International System of Units, Table 3 (watt = volt × ampere) and Appendix B.8, retrieved 2026-10-01. https://www.nist.gov/pml/special-publication-811