How to calculate your electricity bill
kWh = (watts × hours per day × days) ÷ 1,000
cost = kWh × rate per kWh
Example: 1,500W space heater, 8 hrs/day, 18.31¢/kWh (EIA U.S. average, July 2026)
- Daily kWh: (1,500 × 8) ÷ 1,000 = 12 kWh
- Monthly kWh (30 days): 12 × 30 = 360 kWh
- Monthly cost: 360 × $0.1831 = $65.92
The calculator counts a month as 30 days and a year as 365.
Electricity rates by state
Average residential prices from the U.S. Energy Information Administration's Electric Power Monthly, Table 5.6.A, for July 2026 (EIA marks the latest month preliminary). The last column multiplies each price by 899 kWh, the EIA's average monthly use per home in 2022.
| State | ¢/kWh | Cost of 899 kWh |
|---|---|---|
| Hawaii | 48.00 | $432 |
| California | 33.61 | $302 |
| Massachusetts | 30.49 | $274 |
| New York | 29.90 | $269 |
| Rhode Island | 28.29 | $254 |
| New Hampshire | 26.60 | $239 |
| New Jersey | 25.19 | $226 |
| Connecticut | 24.16 | $217 |
| Michigan | 23.05 | $207 |
| Ohio | 19.45 | $175 |
| Illinois | 19.22 | $173 |
| US Average | 18.31 | $165 |
| Georgia | 16.27 | $146 |
| Texas | 15.88 | $143 |
| North Carolina | 15.16 | $136 |
| Florida | 15.03 | $135 |
| Washington | 14.71 | $132 |
| Louisiana | 12.72 | $114 |
Appliance energy usage (at 18.31¢/kWh)
Wattages and hours are typical examples, not measurements; the nameplate or EnergyGuide label on your own appliance governs. Costs use the EIA's U.S. average for July 2026 and a 30-day month.
| Appliance | Watts | Hrs/day | kWh/mo | $/month |
|---|---|---|---|---|
| Central AC | 1,500 | 8 | 360.0 | $65.92 |
| Window AC | 900 | 8 | 216.0 | $39.55 |
| Electric heater | 1,500 | 6 | 270.0 | $49.44 |
| Water heater (electric) | 4,000 | 3 | 360.0 | $65.92 |
| Refrigerator | 150 | 24 | 108.0 | $19.77 |
| Clothes dryer | 5,000 | 1 | 150.0 | $27.47 |
| Electric oven | 2,000 | 1 | 60.0 | $10.99 |
| Dishwasher | 1,800 | 1 | 54.0 | $9.89 |
| Pool pump | 2,000 | 8 | 480.0 | $87.89 |
| TV (LED) | 100 | 5 | 15.0 | $2.75 |
| Desktop computer | 200 | 6 | 36.0 | $6.59 |
| Laptop | 60 | 8 | 14.4 | $2.64 |
| Washing machine | 500 | 1 | 15.0 | $2.75 |
| Microwave | 1,000 | 0.25 | 7.5 | $1.37 |
| Ceiling fan | 75 | 10 | 22.5 | $4.12 |
| LED bulb (×10) | 100 | 6 | 18.0 | $3.30 |
| Hair dryer | 1,800 | 0.1 | 5.4 | $0.99 |
| Coffee maker | 900 | 0.25 | 6.8 | $1.24 |
| EV charger (L2) | 7,200 | 4 | 864.0 | $158.20 |
| Dehumidifier | 500 | 12 | 180.0 | $32.96 |
How to read your electricity meter
Modern digital meters display your cumulative kWh reading directly. Record the reading on two dates (e.g., 1st and 30th of the month), subtract to get kWh used during that period. Analog dials: read left to right; if the pointer is between numbers, use the lower number. Smart meters transmit readings automatically to the utility and often display daily/hourly usage through a web portal or app.
Tips to lower your electric bill
- Switch to LED bulbs, which draw far fewer watts than incandescent bulbs for the same light and last longer.
- Use a programmable or smart thermostat to ease off heating and cooling while you sleep or are out.
- Unplug phantom loads, game consoles, cable boxes, chargers. Every watt drawn around the clock is 0.72 kWh a month.
- Seal air leaks, weather strip doors, caulk windows, so heating and cooling run less.
- Use cold water for laundry, since heating the water is much of what a washer load costs.
- Time-of-use rates, if your utility offers them: run the dishwasher, laundry and car charging off-peak.
- Replace old appliances, comparing the kWh per year on the EnergyGuide labels.
- Ceiling fans + AC together, which can let you set the thermostat a little higher and stay comfortable.
Understanding your electric bill
Your bill typically has three main parts:
- Energy charge, kWh used × rate per kWh. This is the biggest line item.
- Delivery / distribution charge, cost to bring power from the grid to your home, often with a fixed and a per-kWh part.
- Fixed monthly charge, a service fee you pay whatever you use.
- Taxes and surcharges, state and local taxes, renewable energy surcharges, public benefit fees.
Your "effective rate" (total bill ÷ total kWh) includes delivery, fees and taxes, so it is higher than the energy charge alone. Use the effective rate for accurate calculations.
Electricity units explained
- Watt (W), unit of power. A 100W bulb uses 100 watts of power when on.
- Kilowatt (kW), 1,000 watts. A 1.5 kW heater = 1,500W.
- Kilowatt-hour (kWh), unit of energy. 1 kW running for 1 hour = 1 kWh. This is what you're billed for.
- Amp (A), unit of current. Household circuits are commonly rated 15 or 20 amps.
- Volt (V), unit of voltage. Standard US outlets are nominally 120V; large appliances use 240V circuits.
Relationship: Watts = Volts × Amps. Use our Watts/Amps/Volts Calculator for conversions.
Frequently asked questions
How do I calculate my electricity bill?
Work out the kilowatt-hours each device uses and multiply by your price. Watts times hours, divided by 1,000, gives kWh. Say a 2,000 W oven runs an hour a day: that is 2 kWh daily and 60 kWh over 30 days, or $10.99 at 18.31¢ per kWh, the EIA's U.S. residential average for July 2026. Repeat for each appliance and add them up; the Bill tab does this for up to 25 lines.
What is a kilowatt-hour (kWh)?
It is the energy of 1,000 watts flowing for one hour, and it is what the utility bills you for. A 1,500 W hair dryer used for 10 minutes takes 0.25 kWh. According to the EIA, the average U.S. residential customer bought 10,791 kWh in 2022, about 899 a month; compare that with the kWh total printed on your own bill.
How much does it cost to run an air conditioner?
It depends on the unit's draw and how long it runs. As an example, a unit drawing 1,500 W for 8 hours a day uses 360 kWh in 30 days, $65.92 at 18.31¢ per kWh, the EIA's U.S. residential average for July 2026. Take the real wattage from the nameplate. Because SEER is cooling delivered per watt-hour, a 20 SEER system needs 30% less electricity than a 14 SEER one for the same cooling (1 − 14/20).
What uses the most electricity in a home?
Whatever draws several kilowatts for hours at a time: equipment that heats or cools, and car chargers. For example, a 7,200 W Level 2 car charger running 4 hours a day comes to 864 kWh a month, $158.20 at the July 2026 U.S. average. The Bill tab flags whichever of your entries uses the most.
What is the average electric bill in the US?
The EIA reports average use (899 kWh a month per home in 2022) and average price (18.31¢ per kWh in July 2026) separately. Multiplying them gives roughly $164.61 a month, a rough figure since the two are from different periods. Use varies a lot by state: Louisiana households bought the most (14,774 kWh a year) and Hawaii the least (6,178).
How many watts does a refrigerator use?
A fridge cycles on and off, so its nameplate wattage overstates what it uses. The yellow EnergyGuide label gives an estimated kWh per year, which is the better number. A label reading 450 kWh a year, for example, works out to $82.40 a year at 18.31¢ per kWh, the EIA's U.S. residential average for July 2026.
How do I find my electricity rate?
Your bill lists the energy or supply charge per kWh, often alongside delivery charges, fixed fees and taxes. Dividing the bill's total by the kWh used gives your all-in rate, the best number to enter here. For a sense of range, in July 2026 the EIA's state averages ran from 12.72¢ in Louisiana to 48.00¢ in Hawaii.
Does turning off lights save electricity?
Yes, though with LEDs the amounts are small. A 10 W LED lit 10 hours a day uses 0.1 kWh a day, about $6.68 a year at the July 2026 U.S. average; switching it off for 4 of those hours saves about $2.67 a year. Heaters, air conditioning and older high-wattage bulbs are where switching off matters more.
How much electricity does a TV use?
Power draw depends on screen size, technology and brightness, so check the EnergyGuide label or the spec sheet. As an example, a set drawing 100 W for 5 hours a day uses 15 kWh a month, $2.75 at 18.31¢ per kWh, the EIA's U.S. residential average for July 2026.
What is a phantom load?
Phantom or standby load is power drawn by equipment that is switched off but still plugged in: set-top boxes, consoles, chargers, anything with a clock or remote. Each 10 W drawn around the clock adds 7.2 kWh a month, $1.32 at the July 2026 U.S. average. A plug-in meter shows what yours draw; a smart power strip can cut them off.
How do I convert watts to kWh?
Multiply watts by hours and divide by 1,000. A 200 W desktop running 8 hours a day for 30 days: 200 × 8 × 30 ÷ 1,000 = 48 kWh.
How much does it cost to charge an electric car?
Multiply the energy you put in by your rate. Adding 60 kWh costs $10.99 at 18.31¢ per kWh, the EIA's U.S. residential average for July 2026, before charging losses. A Level 2 charger drawing 7,200 W (240 V × 30 A) for 4 hours delivers 28.8 kWh from the wall, $5.27 at that price. Public fast chargers set their own prices.