How to Calculate Your Electricity Bill (2026)

Your electricity bill is the product of how much power your appliances draw (in watts) and how long you run them. Understanding that relationship lets you spot which devices are costing you the most and estimate savings before making changes. Use the Electricity Cost Calculator to do this instantly.

The Formula Behind Every Electricity Bill

Utilities bill in kilowatt-hours (kWh) — one kilowatt of power consumed for one hour. The math is straightforward: multiply the device wattage by hours of use, divide by 1,000 to convert to kWh, then multiply by your rate. A 1,500-watt space heater running 8 hours a day at $0.15/kWh costs $1.80 per day, or roughly $54 per month. The same calculation applies to any appliance: find the wattage on the label or spec sheet, estimate daily run time, and multiply by your utility rate.

If your bill shows total kWh consumed, divide the total charge (excluding fixed fees) by the kWh used to find your effective rate. This is the number to use in all estimates.

Typical Appliance Consumption

Most household costs concentrate in a small number of high-draw devices. Knowing typical wattages helps you prioritize where to look.

Heating, cooling, and water heating typically account for 50–70% of a residential electricity bill. Targeting those systems has a far greater impact than unplugging phone chargers.

Reading and Interpreting Your Bill

Most utility bills have two cost components: a fixed service charge (usually $5–$20/month regardless of usage) and a variable energy charge per kWh. Some utilities add a demand charge based on your peak draw in a 15-minute window — common in commercial accounts and some residential time-of-use plans. If you're on a tiered rate, the first block of kWh is cheaper and usage above a threshold is billed at a higher rate. Knowing which tier you're in changes which appliances are worth replacing first. Time-of-use plans add another layer: running the dishwasher at 11 PM instead of 6 PM can cut that cycle's cost by 30–50%.

Use the Electricity Cost Calculator to do this instantly — enter wattage, daily hours, and your rate to see daily, monthly, and annual cost for any device.