Utility Bills
Electricity Rate Cost per kWh
Your electricity rate is the price you pay for each kilowatt-hour of energy. It is the number that turns energy use into cost.
Where to find your rate
Look on your electric bill for a line such as energy charge, supply charge, delivery charge, or total cost per kWh. Some bills make this easy, while others split the cost across several line items.
For a practical household estimate, divide the bill's electricity-related charges by total kWh used. This gives an effective average rate.
Average Rate = Total Electricity Charges / Total kWh UsedSupply rate vs effective rate
Some utility bills show a low-looking supply rate, but the final bill also includes delivery charges, riders, taxes, fixed fees, or other line items. If you only use the supply rate, you may underestimate the real cost of running an appliance.
For household planning, an effective average rate is often better. Add the electricity-related charges on the bill, divide by total kWh used, and use that number in the calculator. This will not perfectly model every fee, but it usually gives a more realistic comparison between appliances.
How rate changes cost
| Rate | Cost for 10 kWh | Cost for 100 kWh |
|---|---|---|
| $0.12/kWh | $1.20 | $12.00 |
| $0.17/kWh | $1.70 | $17.00 |
| $0.25/kWh | $2.50 | $25.00 |
Time-of-use rates
Some utilities charge different rates by time of day. If your plan has peak and off-peak rates, use the rate that matches when the appliance runs.
Which rate should you enter?
| Situation | Rate to use | Why it helps |
|---|---|---|
| Flat-rate plan | Your average $/kWh | Simple and usually good enough for daily estimates. |
| Time-of-use plan | The rate for the time the appliance runs | Useful for EV charging, laundry, dishwashing, and overnight loads. |
| Hard-to-read bill | Total charges divided by total kWh | Creates a practical effective rate for comparisons. |
| Solar or net metering | Your marginal or exported-energy value if known | Costs can depend on when power is used and how credits are applied. |
Why rate changes matter
Electricity rate has a direct one-to-one effect on estimated cost. If your rate doubles, the estimated appliance cost doubles for the same watts and hours. That is why the same 10 kWh of appliance use costs $1.20 at $0.12/kWh, $1.70 at $0.17/kWh, and $2.50 at $0.25/kWh.
Rate differences are especially important for appliances that use many kWh per month, such as space heaters, air conditioners, dryers, water heaters, pool pumps, and EV chargers. Small changes in rate may not matter much for a laptop or fan, but they can become noticeable for high-use appliances.
Electricity rate FAQ
What is a good default electricity rate?
WattCostGuide uses $0.17/kWh as a practical default for examples, but your own bill is better. Rates vary by state, utility, plan, season, and time of day.
Should I include fixed monthly fees?
For comparing appliance choices, fixed monthly fees are usually less important because you pay them whether or not one appliance runs. For a whole-bill average rate, including them can show the full cost of electricity service.
Why is my bill rate different from my advertised rate?
Advertised rates may show only part of the bill. Delivery charges, taxes, riders, and other fees can make the effective cost per kWh higher than the supply rate alone.
Try different rates in calculators
These appliance calculators make it easy to compare lower, average, and high electricity rates.
Related electricity guides
Learn how rate connects with watts, kWh, and appliance running cost.