Expert Reviewed
Marcus Webb, B.Eng, Applied Mathematics SpecialistUpdated June 1, 2026Our Standards →

Last updated:

Electricity Cost Calculator

Enter any appliance wattage, hours used per day, and your electricity rate — instantly see the daily, monthly, and yearly cost. Find your biggest power hogs ...

Back to Tools

Electricity Cost Calculator

Ad-FreeAI-Powered

Find out exactly how much your appliances cost to run. Enter watts, hours per day, and your electricity rate — get daily, monthly, and annual costs instantly.

Enter values above to see results.

About This Calculator

Related Articles

Reviewed by CalculatorApp.me Tools Team

Electricity Cost Calculator — Complete Energy Guide

Calculate electricity costs for any appliance, estimate monthly bills, compare energy-efficient alternatives, and find ways to reduce power consumption.

$0.16/kWh

US avg (2024)

10,500 kWh

US avg annual

$137/mo

US avg bill

1 kWh

= 3,412 BTU

Understanding Electricity Costs

A kilowatt-hour (kWh) is the standard unit of electrical energy consumption. It represents the amount of energy used when a 1,000-watt appliance runs for one hour. Your electricity bill is calculated by multiplying your total kWh consumption by your utility's rate per kWh, plus applicable taxes, fees, and demand charges.

The average U.S. household consumes approximately 10,500 kWh per year (about 886 kWh/month), according to the U.S. Energy Information Administration (EIA). The nationwide average retail electricity price was $0.163 per kWh in 2024, though rates vary dramatically — from $0.10/kWh in states like Louisiana and Idaho to over $0.35/kWh in Hawaii and Connecticut.

Understanding kWh consumption helps you identify energy-hungry appliances, evaluate the ROI of energy-efficient upgrades (LED lighting, ENERGY STAR appliances, heat pumps), estimate solar panel payback periods, and take advantage of time-of-use (TOU) pricing to shift usage to off-peak hours.

Electricity Cost Formulas

Basic Appliance Cost
Daily Cost ($):
  = (Watts × Hours/Day) ÷ 1,000 × Rate

Monthly Cost ($):
  = Daily Cost × 30

Annual Cost ($):
  = Daily Cost × 365

Example: 60W light bulb, 8 hrs/day
  Daily kWh = (60 × 8) ÷ 1,000 = 0.48 kWh
  Daily cost = 0.48 × $0.16 = $0.077
  Monthly = $0.077 × 30 = $2.30
  Annual = $0.077 × 365 = $28.03

Tip: Check wattage on appliance label
or nameplate (watts or amps × volts).

This formula works for any appliance with a constant wattage draw. For variable-load devices (AC units, refrigerators), use the average or rated wattage.

Watts from Amps & Volts
Watts = Amps × Volts

For DC and single-phase AC:
  W = A × V

For three-phase AC:
  W = A × V × √3 × Power Factor
  (PF typically 0.8–0.95)

Example: Hair dryer draws 12.5 A at 120V
  W = 12.5 × 120 = 1,500 watts
  = 1.5 kW
  Running 15 min/day:
  kWh = 1.5 × (15/60) = 0.375 kWh
  Daily cost = 0.375 × $0.16 = $0.06

US standard: 120V (15/20A circuits)
US heavy-duty: 240V (dryer, range, HVAC)
Europe: 230V  |  Japan: 100V

Most appliance labels show wattage directly. Use Amps × Volts only when wattage isn't listed.

Monthly Bill Estimation
Total Monthly Bill ($):
  = Total kWh × Blended Rate
  + Fixed Charges + Taxes

Blended rate includes:
  • Base rate (generation)
  • Transmission charges
  • Distribution charges
  • Renewable surcharges

Example: 900 kWh/month
  Energy: 900 × $0.12 = $108.00
  Delivery: 900 × $0.04 = $36.00
  Fixed charge: $12.50
  Taxes (6%): $9.39
  Total: $165.89

Tiered pricing (e.g. California):
  Tier 1 (0-350 kWh):  $0.11
  Tier 2 (351-800 kWh): $0.16
  Tier 3 (801+ kWh):    $0.31

Your bill includes more than just energy charges. Fixed fees, delivery charges, taxes, and surcharges can add 30-50% to the base energy cost.

Energy Savings & Payback
Annual Savings ($):
  = (Old kWh - New kWh) × Rate × 365

Payback Period (years):
  = Upgrade Cost ÷ Annual Savings

Example: Replace 60W incandescent
with 9W LED (same 800 lumens)
  Old: 60W × 8 hrs = 480 Wh/day
  New: 9W × 8 hrs = 72 Wh/day
  Saved/day: 408 Wh = 0.408 kWh
  Annual savings: 0.408 × 365 × $0.16
  = $23.83 per bulb per year

  LED cost: $3.00
  Payback: 3.00 ÷ 23.83 = 46 days!

LED lifespan: ~25,000 hours
Incandescent: ~1,000 hours
You also save on bulb replacements.

LEDs are the single best energy ROI for most homes — 85% less energy than incandescent with 25× longer lifespan. The payback is measured in weeks, not years.

Common Appliance Energy Consumption

ApplianceWattageTypical UseDaily kWhMonthly Cost*
Central AC3,500 W8 hrs/day28.0 kWh$134.40
Electric water heater4,500 W3 hrs/day13.5 kWh$64.80
Clothes dryer5,000 W1 hr, 5×/wk3.6 kWh†$17.14
Refrigerator150 W24 hrs (cycling)3.6 kWh$17.28
Electric oven/range2,500 W1 hr/day2.5 kWh$12.00
Dishwasher1,800 W1 hr/day1.8 kWh$8.64
Washing machine500 W1 hr, 5×/wk0.36 kWh†$1.71
Desktop computer200 W8 hrs/day1.6 kWh$7.68
LED light (9W)9 W8 hrs/day0.072 kWh$0.35
Incandescent (60W)60 W8 hrs/day0.48 kWh$2.30
Space heater1,500 W6 hrs/day9.0 kWh$43.20
EV charger (Level 2)7,200 W4 hrs/day28.8 kWh$138.24

*At US average $0.16/kWh. †Daily average from weekly usage. Actual consumption varies by model, usage pattern, and climate.

US Electricity Rates by State (Selected)

StateAvg Rate (¢/kWh)900 kWh BillPrimary SourcesRate Type
Hawaii43.3¢$390Oil, solar, windTiered
Connecticut29.8¢$268Nuclear, natural gasSupply + delivery
California28.4¢$256Natural gas, solar, windTiered + TOU
New York23.5¢$212Nuclear, natural gas, hydroSupply + delivery
Texas13.8¢$124Natural gas, windDeregulated, flat
Florida13.7¢$123Natural gas, nuclear, solarFlat
Ohio13.3¢$120Natural gas, coal, nuclearDeregulated
Idaho10.3¢$93Hydro, windFlat + tiered
Louisiana10.1¢$91Natural gasFlat
US Average16.3¢$147MixVaries

Source: EIA, 2024 data. Rates include all components (generation, transmission, distribution). Actual bills depend on usage, demand charges, and local surcharges.

Time-of-Use (TOU) Pricing Explained

Off-Peak

9 PM – 7 AM

$0.08–$0.12/kWh

Cheapest rates. Run dishwasher, laundry, and EV charging overnight. Grid demand is lowest.

Mid-Peak

7 AM – 4 PM

$0.14–$0.20/kWh

Moderate rates during business hours. Solar panels offset daytime usage in many markets.

On-Peak

4 PM – 9 PM

$0.25–$0.50/kWh

Most expensive. Grid demand peaks as people return home. Avoid heavy appliance use during this window.

TOU pricing is offered by most utilities and can save 10-30% on your bill if you shift heavy loads to off-peak hours. Some plans offer "super off-peak" rates for overnight EV charging.

History of Electricity & Metering

1879

Thomas Edison demonstrates the first commercially practical incandescent light bulb at Menlo Park, New Jersey — launching the era of residential electricity.

1882

Edison opens the Pearl Street Station in Manhattan, the first commercial central power plant, supplying electricity to 85 customers at a rate of about $0.24/kWh (equivalent to ~$7/kWh today).

1888

Oliver Shallenberger invents the induction watt-hour meter at Westinghouse, enabling accurate measurement of electricity consumption — the basis of modern billing.

1935

The Rural Electrification Act brings electricity to rural America. By 1936, only 11% of rural farms had power; by 1960, 97% were electrified.

1992

The Energy Policy Act introduces ENERGY STAR labeling and deregulates wholesale electricity markets, giving consumers more choice and transparency on energy costs.

2009–present

Smart meters and advanced metering infrastructure (AMI) replace mechanical meters across the US, enabling time-of-use pricing, real-time consumption tracking, and demand response programs.

Research & Industry Data

U.S. Energy Information Administration (EIA)

The primary federal agency for energy statistics. Publishes monthly electricity retail prices, consumption data, and state-level rate comparisons for all sectors.

Visit U.S. Energy Information Administration (EIA)

ENERGY STAR (EPA/DOE)

Joint EPA/DOE program certifying energy-efficient products. ENERGY STAR appliances use 10-50% less energy than standard models, with verified test data.

Visit ENERGY STAR (EPA/DOE)

Lawrence Berkeley National Laboratory

Publishes definitive research on standby power ('vampire loads'), appliance energy use, and residential energy consumption trends used by policymakers.

Visit Lawrence Berkeley National Laboratory

National Renewable Energy Laboratory (NREL)

NREL researches solar, wind, and grid integration. Their PVWatts Calculator estimates solar panel electricity production and savings for any US location.

Visit National Renewable Energy Laboratory (NREL)

Common Electricity Cost Myths vs Facts

MYTH

Turning lights on and off uses more energy than leaving them on.

FACT

False for all modern lighting. Turning off any light saves energy instantly. The startup surge for LEDs and CFLs is negligible (< 1 second of runtime). For fluorescent tubes, the break-even point is about 15 minutes — if you'll be gone longer, turn them off.

MYTH

Chargers plugged in but not connected don't use electricity.

FACT

Chargers and power adapters draw small 'vampire loads' (0.1-0.5W) even when idle. Across a typical home with 20-40 devices, standby power can account for 5-10% of annual electricity cost ($50-$100/year). Smart power strips eliminate this.

MYTH

Running appliances at night always costs less.

FACT

Only if your utility offers time-of-use (TOU) pricing. About 40% of US utilities now offer TOU plans where off-peak rates (9 PM–7 AM) are 30-60% cheaper than peak. Check your bill — if you're on a flat rate, time of day doesn't matter.

MYTH

Higher-wattage appliances always cost more to run.

FACT

Total cost depends on wattage AND runtime. A 1,500W space heater running 2 hours costs $0.48. A 150W TV running 12 hours costs $0.29. A 3W smart speaker running 24/7 costs $0.01/day. Always calculate kWh, not just watts.

MYTH

Solar panels eliminate your electricity bill entirely.

FACT

Most grid-tied solar systems offset 70-100% of energy use, but you'll still pay fixed charges, delivery fees, and demand charges ($10-$30/month minimum). Net metering credits vary by state and may not cover all tiers.

MYTH

All ENERGY STAR appliances save the same amount of energy.

FACT

Savings vary wildly by category. ENERGY STAR refrigerators save ~10% vs standard. Heat pumps can save 50% vs electric resistance. LED bulbs save 75-85% vs incandescent. Always check the yellow EnergyGuide label for projected annual cost.

Frequently Asked Questions

What is a kilowatt-hour (kWh)?+

A kilowatt-hour is a unit of energy equal to 1,000 watts consumed for one hour. For example, a 100-watt light bulb running for 10 hours uses 1 kWh. Your utility charges you per kWh consumed.

How do I calculate the cost to run an appliance?+

Multiply the appliance's wattage by hours of use, divide by 1,000 to get kWh, then multiply by your electricity rate. For example: 1,500W heater × 4 hours ÷ 1,000 × $0.16 = $0.96 per session.

What is the average electricity rate in the US?+

As of 2024, the national average residential electricity rate is approximately $0.163 per kWh (EIA data). Rates range from $0.10/kWh in states like Louisiana to $0.43/kWh in Hawaii.

Why is my electric bill so high?+

Common culprits: HVAC (30-50% of bills), electric water heater (14-18%), old refrigerator/freezer (5-10%), pool pump, space heaters, and standby power from dozens of connected devices. An energy audit identifies the biggest drains.

What is time-of-use (TOU) pricing?+

TOU pricing charges different rates based on when you use electricity. Peak hours (typically 4–9 PM) cost 2-3× more than off-peak (overnight). Shifting laundry, dishwasher, and EV charging to off-peak can save 10-30%.

How much electricity does an EV use?+

The average EV uses about 30 kWh per 100 miles. At $0.16/kWh, that's $4.80 per 100 miles — compared to ~$12-15 for a gasoline car at 30 MPG and $3.50/gallon.

What are vampire loads (standby power)?+

Vampire loads are the electricity devices consume when plugged in but not actively in use — chargers, cable boxes, gaming consoles, smart home devices. They account for 5-10% of household electricity use, or $50-$100/year.

How do I read my electricity meter?+

Digital meters display kWh directly. For analog meters, read the dials left to right, recording the lower number when the pointer is between two digits. Subtract last month's reading from current to get monthly kWh.

Is it cheaper to heat with gas or electricity?+

In most US markets, natural gas heating costs 30-50% less than electric resistance heating per BTU. However, electric heat pumps (300% efficient) can be cheaper than gas in moderate climates, especially with TOU rates.

How do solar panels affect my electricity cost?+

Solar panels generate electricity during daylight hours, reducing grid consumption. Net metering credits you for excess power sent to the grid. A typical residential system (6-10 kW) can offset 70-100% of electricity costs.

What is demand charge on commercial bills?+

Demand charges are based on your peak power draw (kW) during a billing period, not total energy (kWh). If your business briefly runs all equipment simultaneously, that peak sets your demand charge for the entire month.

How much can LED lighting save?+

LED bulbs use 75-85% less energy than incandescent and last 25× longer. Replacing 30 incandescent bulbs with LEDs saves approximately $500-$700 per year for a typical home. The payback period is usually 1-3 months per bulb.

References & Sources

  • U.S. Energy Information Administration (EIA). "Electric Power Monthly — Average Retail Price of Electricity." 2024. eia.gov
  • U.S. Department of Energy. "Estimating Appliance and Home Electronic Energy Use." energy.gov
  • ENERGY STAR. "Certified Products — Savings and Specifications." U.S. EPA and DOE. energystar.gov
  • Lawrence Berkeley National Laboratory. "Standby Power Summary Table." standby.lbl.gov
  • NREL. "PVWatts Calculator." National Renewable Energy Laboratory. pvwatts.nrel.gov
  • Edison, Thomas A. (1882). "Central Station Electric Lighting." Edison Papers, Rutgers University. Historical context for the Pearl Street Station and early electricity pricing.

Calculate Your Electricity Costs Instantly

Find out exactly how much any appliance costs to run per day, month, and year — and discover where to cut your power bill.

Try the Electricity Cost Calculator →

See Also