Watts: conversions & definition
A watt is one joule per second: a rate of energy transfer. Watts measure power; watt-hours measure energy accumulated over time.
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Each row converts one W. Open a converter to enter any value and see its formula, worked example and reference table. Results below are rounded to 10 significant digits.
| Convert to | Equivalent value | Calculator |
|---|---|---|
| Kilowatts (kW) | ≈ 0.001 | Convert W to kW |
| Megawatts (MW) | ≈ 0.000001 | Convert W to MW |
| Mechanical horsepower (hp) | ≈ 0.00134102209 | Convert W to hp |
| Metric horsepower (PS) | ≈ 0.001359621617 | Convert W to PS |
| BTU per hour (Btu IT/h) | ≈ 3.412141633 | Convert W to Btu IT/h |
| Attowatts (aW) | ≈ 1e+18 | Convert W to aW |
| Centiwatts (cW) | ≈ 100 | Convert W to cW |
| Decawatts (daW) | ≈ 0.1 | Convert W to daW |
| Deciwatts (dW) | ≈ 10 | Convert W to dW |
| Exawatts (EW) | ≈ 1e-18 | Convert W to EW |
| Femtowatts (fW) | ≈ 1e+15 | Convert W to fW |
| Gigawatts (GW) | ≈ 1e-9 | Convert W to GW |
| Hectowatts (hW) | ≈ 0.01 | Convert W to hW |
| Microwatts (µW) | ≈ 1,000,000 | Convert W to µW |
| Milliwatts (mW) | ≈ 1,000 | Convert W to mW |
| Nanowatts (nW) | ≈ 1,000,000,000 | Convert W to nW |
| Petawatts (PW) | ≈ 1e-15 | Convert W to PW |
| Picowatts (pW) | ≈ 1e+12 | Convert W to pW |
| Quectowatts (qW) | ≈ 1e+30 | Convert W to qW |
| Quettawatts (QW) | ≈ 1e-30 | Convert W to QW |
| Ronnawatts (RW) | ≈ 1e-27 | Convert W to RW |
| Rontowatts (rW) | ≈ 1e+27 | Convert W to rW |
| Terawatts (TW) | ≈ 1e-12 | Convert W to TW |
| Yoctowatts (yW) | ≈ 1e+24 | Convert W to yW |
| Yottawatts (YW) | ≈ 1e-24 | Convert W to YW |
| Zeptowatts (zW) | ≈ 1e+21 | Convert W to zW |
| Zettawatts (ZW) | ≈ 1e-21 | Convert W to ZW |
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