Kilowatt-hours to Watt-hours Converter

Many smaller batteries are rated in watt-hours: laptop and drone batteries, e-bike packs and portable power stations. Electricity meters, bills and home batteries use kilowatt-hours. To compare them, put both in the same unit. Since 1 kWh = 1,000 Wh, this page simply moves the decimal point three places to the right:

• 0.1 kWh = 100 Wh
• 0.75 kWh = 750 Wh
• 1.2345 kWh = 1234.5 Wh
• 13.5 kWh = 13500 Wh

A 750 Wh portable station holds 0.75 kWh, so you can check it against a device's daily kWh use directly.

A device's energy use is its power in watts multiplied by the hours it runs. A 60 W lamp on for 5 hours uses 60 × 5 = 300 Wh. Swap the units on this page and enter 300 to see that it is 0.3 kWh, the figure a bill would count.

Solar output works the same way. A 400 W panel producing at full rating for the equivalent of 4 hours delivers 1600 Wh, which is 1.6 kWh.

To estimate cost, multiply the kWh figure by the price per kWh on your bill. Converting to kWh first avoids the easy slip of multiplying watt-hours by a per-kWh price, which overstates the cost a thousand times.

Phone and power-bank batteries are often sold by milliamp-hours, which measure charge, not energy. To get watt-hours you need the battery voltage: Wh = mAh × V ÷ 1000. A 10,000 mAh pack at 3.7 V holds 37 Wh, which is 0.037 kWh. This converter has no mAh option, because the answer depends on a voltage it cannot know, so do that step first and then convert the Wh.

Fractions of a kilowatt-hour convert cleanly: 0.0005 kWh is 0.5 Wh. In the other direction, small Wh values show up to five significant figures, so 99.9 Wh appears as 0.0999 kWh. Results of 100 Wh or more are shown to two decimals, which is already finer than any meter or battery label reads.