Electricity Cost Calculator
Estimate energy-use cost from watts and runtime, or enter total kilowatt-hours.
Quick answer
Electricity cost = watts × hours ÷ 1,000 × price per kWh. At the EIA U.S. average residential rate of 18.16¢/kWh (June 2026), 1 kWh costs $0.18, a 1,500 W space heater costs $0.27 per hour, and 100 kWh costs $18.16. State averages run from 12.72¢ in Nevada to 47.18¢ in Hawaii, so the same appliance can cost 3.7× more to run depending on where you live. Enter your watts and runtime below, or pick your state for a dated EIA reference price. Reviewed September 17, 2026.
EIA residential reference: August 2026. Not an individual utility tariff.
Appliance power examples
Example assumptions only. Actual draw, cycling and runtime depend on the model and settings.
Cost for your period
$65.38
360 kWh over 30 days at 0.1816 USD/kWh.
- Average daily cost across the period
- $2.18
- 365-day projection of this usage pattern
- $795.41
- 365-day projected consumption
- 4,380 kWh
The projection repeats this period's average daily usage for 365 days. It does not predict seasonal consumption, future prices or your complete bill.
24-Hour Home Demand & Time-of-Use Curve
Heat Pump & Appliance Efficiency Upgrades
Standard Electric Water Heater
4,500 Watts • 3 hours operating/day
Hybrid Inverter Heat Pump
500 Watts compressor • 6 hours operating/day
Watts, kilowatt-hours and operating days
EIA distinguishes power from energy: watts describe power; kilowatt-hours describe energy used over time. A 1,200-watt device running for one hour consumes 1.2 kWh. The expression is watts x hours / 1,000, not watts per hour.
- Period energy
- watts x hours per active day x active days / 1,000
- Period cost
- period kWh x price per kWh
- 365-day projection
- period cost / period days x 365
For example, a 1,000-watt device used for one hour on one day in a 30-day period costs $0.15 at $0.15/kWh. Repeating that pattern gives about $1.83 over 365 days. Assuming use every day instead would cost $54.75, a different scenario.
Cost lookups at your selected rate
Rate: 0.1816 USD/kWh. Costs rounded to cents; other charges are not separately calculated.
| Energy | Cost |
|---|---|
| 1.8 kWh | $0.33 |
| 7 kWh | $1.27 |
| 49 kWh | $8.90 |
| 50 kWh | $9.08 |
| 95 kWh | $17.25 |
| 130 kWh | $23.61 |
| 150 kWh | $27.24 |
| 240 kWh | $43.58 |
| 250 kWh | $45.40 |
| 336 kWh | $61.02 |
| 350 kWh | $63.56 |
| 400 kWh | $72.64 |
| 420 kWh | $76.27 |
| 700 kWh | $127.12 |
| 1,500 kWh | $272.40 |
| 2,100 kWh | $381.36 |
| 4,000 kWh | $726.40 |
| 4,500 kWh | $817.20 |
| Power | 1 hour | 8 hours | 8h/day x 30 days |
|---|---|---|---|
| 15 W | $0.00 | $0.02 | $0.65 |
| 50 W | $0.01 | $0.07 | $2.18 |
| 250 W | $0.05 | $0.36 | $10.90 |
| 700 W | $0.13 | $1.02 | $30.51 |
| 800 W | $0.15 | $1.16 | $34.87 |
| 1200 W | $0.22 | $1.74 | $52.30 |
| 1500 W | $0.27 | $2.18 | $65.38 |
| 1600 W | $0.29 | $2.32 | $69.73 |
| 2000 W | $0.36 | $2.91 | $87.17 |
| 3000 W | $0.54 | $4.36 | $130.75 |
| 4500 W | $0.82 | $6.54 | $196.13 |
| 7700 W | $1.40 | $11.19 | $335.60 |
Cost to run common loads for 1 hour and per month at state rates
Pure wattage math (watts × hours ÷ 1,000) at each state's EIA average residential price: a 1,500 W space heater (4 h/day), a 3,500 W central AC (8 h/day) and a 3,000 W electric dryer (1 h/day), each over a 30-day month. Five cheapest and five most expensive states plus the U.S. average.
| State | ¢/kWh | Space heater (1,500 W) | Central AC (3,500 W) | Electric dryer (3,000 W) | |||
|---|---|---|---|---|---|---|---|
| 1 hour | 4 h/day × 30 d | 1 hour | 8 h/day × 30 d | 1 hour | 1 h/day × 30 d | ||
| U.S. average | 18.16 | $0.27 | $32.69 | $0.64 | $152.54 | $0.54 | $16.34 |
| Nevada | 12.72 | $0.19 | $22.90 | $0.45 | $106.85 | $0.38 | $11.45 |
| Louisiana | 12.87 | $0.19 | $23.17 | $0.45 | $108.11 | $0.39 | $11.58 |
| North Dakota | 13.31 | $0.20 | $23.96 | $0.47 | $111.80 | $0.40 | $11.98 |
| Utah | 13.31 | $0.20 | $23.96 | $0.47 | $111.80 | $0.40 | $11.98 |
| Idaho | 13.37 | $0.20 | $24.07 | $0.47 | $112.31 | $0.40 | $12.03 |
| Hawaii | 47.18 | $0.71 | $84.92 | $1.65 | $396.31 | $1.42 | $42.46 |
| Maine | 32.11 | $0.48 | $57.80 | $1.12 | $269.72 | $0.96 | $28.90 |
| Massachusetts | 30.48 | $0.46 | $54.86 | $1.07 | $256.03 | $0.91 | $27.43 |
| California | 29.75 | $0.45 | $53.55 | $1.04 | $249.90 | $0.89 | $26.78 |
| Alaska | 29.41 | $0.44 | $52.94 | $1.03 | $247.04 | $0.88 | $26.47 |
Source: EIA Electric Power Monthly, Table 5.6.A, residential average price, June 2026 (data period 2026-08). Energy charge only; fixed customer charges, taxes and riders are extra.
Deeper dives: space heater cost to run by state, electric water heater cost per month by state, the appliance energy cost hub (for example space heater and electric water heater), and the whole-home electric bill estimator.
EIA residential reference prices
U.S. average: 18.16 cents/kWh for August 2026. Source data collected 2026-10-25. These are residential sales averages, not a guaranteed tariff or forecast.
| State | Cents/kWh | Observation month |
|---|---|---|
| Hawaii | 47.18 | August 2026 |
| Maine | 32.11 | August 2026 |
| Connecticut | 24.51 | August 2026 |
| California | 29.75 | August 2026 |
| New York | 28.65 | August 2026 |
| Pennsylvania | 21.77 | August 2026 |
| Michigan | 22.99 | August 2026 |
| Florida | 14.99 | August 2026 |
| Texas | 15.91 | August 2026 |
| Missouri | 16.02 | August 2026 |
| Nebraska | 13.54 | August 2026 |
| North Dakota | 13.31 | August 2026 |
When a simple usage estimate differs from your bill
Fixed customer charges, demand charges, usage tiers, bill credits and time-of-use pricing can change the total. A state average cannot reproduce these rules. In a hypothetical time-of-use comparison, 2 kWh costs $0.60 at $0.30/kWh or $0.20 at $0.10/kWh; the applicable hours and prices depend on the utility.
Appliances that cycle need an appropriate runtime or measured average power. The FTC explains EnergyGuide labels, whose annual kWh figures help compare appliances under stated test assumptions. A label's estimated cost is not your personal bill.
Related calculations: EV charging, heat pumps, solar sizing and home energy audit. Savings depend on your actual usage and project assumptions, not a universal percentage.
Reviewed September 17, 2026. Estimates depend on the rate plan, usage pattern and operating conditions.
Frequently Asked Questions
What is the formula for electricity cost?
Energy in kWh equals watts x operating hours / 1,000. Multiply kWh by the price per kWh for an energy-use cost estimate. For repeated use, include the number of active days in the period.
How much does 150 kWh cost?
At $0.15 per kWh, 150 kWh costs $22.50. At $0.30 per kWh, it costs $45. Your utility bill may include additional charges or use a tiered or time-of-use tariff.
Why does annual cost depend on active days?
The 365-day projection repeats your entered pattern: period kWh / period days x 365 x rate. A device used once in 30 days is not assumed to run every day of the year. Seasonality, changes in prices and non-repeating usage are not predicted.
Why does a zero rate give zero cost?
A zero per-kWh rate gives zero usage cost. Fixed fees, demand charges and other bill items can still apply. This calculator does not separately model those charges.
Are the state reference rates my utility tariff?
No. EIA residential prices are state-level averages, not an individual utility offer. The observation month is shown separately from the collection date. Your rate plan can vary by season, usage tier, time of day and customer class.
Can I use nameplate watts for a refrigerator?
Appliances can cycle or vary their power draw. Multiplying a running wattage by 24 hours may overstate energy use. Annual kWh from an EnergyGuide label, a measured average power draw, or an appropriate active runtime may be a better basis. Avoid counting the same cycling adjustment twice.
How much does it cost to run a 1,500 W space heater for an hour?
A 1,500-watt heater uses 1.5 kWh per hour, so at the EIA U.S. average of 18.16 cents/kWh (June 2026) one hour costs $0.27. Four hours a day for 30 days is 180 kWh, or $32.69 a month at the U.S. average, $22.90 in Nevada and $84.92 in Hawaii.
How much does central air conditioning cost per month?
A 3,500-watt central AC that runs 8 hours a day uses 28 kWh per day, or 840 kWh over 30 days. That is $152.54 at the U.S. average rate of 18.16 cents/kWh, $106.85 in Nevada and $396.31 in Hawaii. Real compressor runtime depends on the thermostat setting, home insulation and outdoor temperature, so use your own hours.
What is the cheapest and most expensive state for electricity in 2026?
In EIA's June 2026 residential data, Nevada is cheapest at 12.72 cents/kWh, followed by Louisiana (12.87), North Dakota (13.31), Utah (13.31), Idaho (13.37). Hawaii is the most expensive at 47.18 cents/kWh, followed by Maine (32.11), Massachusetts (30.48), California (29.75), Alaska (29.41). The U.S. average is 18.16 cents/kWh.