What is a kWh? The unit on your electric bill

By Felipe Guilherme de Oliveira Bueno. Updated November 11, 2026.

A kilowatt-hour (kWh) is the amount of electricity used by 1,000 watts running for one hour. It is the unit your utility bills you for.

Watts and kilowatt-hours are different things

Watts measure power: how fast something uses electricity at a given moment. Kilowatt-hours measure energy: the total used over time. A car comparison helps. Watts are the speed. Kilowatt-hours are the miles driven.

What one kWh looks like

• A 10-watt LED bulb running for 100 hours.
• A 100-watt television running for 10 hours.
• A 1,000-watt microwave running for 1 hour.
• A 1,500-watt space heater running for 40 minutes.

What one kWh costs

The U.S. average residential price is 18.19 cents per kWh (January to August 2026, EIA). It runs from 12.46 cents in North Dakota to 46.41 cents in Hawaii. See the full state ranking.

Finding it on your bill

Look for "kWh used" or "usage" for the billing period. Divide the energy charges by that number to get what you actually pay per kWh. Many bills also have a fixed monthly customer charge that you pay no matter how much you use.

How we get these numbers: yearly electricity use comes from the ENERGY STAR certified product lists, measured with the federal test procedure. The rate is the average residential price the U.S. Energy Information Administration reports for each state, January to August 2026. Your own bill depends on your utility, your plan and how you use the appliance. See sources.