What is an Electricity Bill Calculator?
An electricity bill calculator estimates your monthly electric costs based on the appliances you use, their wattage, and how many hours they run. Understanding what consumes the most electricity helps you reduce your bills and make smarter energy choices.
Your electricity bill is calculated in kilowatt-hours (kWh)—the amount of energy used. A 1000-watt device running for 1 hour uses 1 kWh. The average US rate is about $0.12-0.15 per kWh, but it varies significantly by state and utility company.
Track Appliances
See exactly which devices cost you the most
Monthly Estimates
Predict your electricity bill before it arrives
Find Savings
Identify energy hogs and opportunities to cut costs
Compare Options
See savings from switching to efficient appliances
Typical wattage of common appliances:
- Air conditioner (central) — 3000-5000W (biggest bill contributor)
- Electric water heater — 4000-5500W (cycles on/off throughout day)
- Refrigerator — 100-400W (runs 24/7, but cycles)
- Gaming PC — 300-800W under load
- LED light bulb — 8-15W (vs. 60W incandescent)
Appliance running costs and rate reference
The formula behind every row below is the same one the calculator uses: watts multiplied by hours per day, divided by 1,000, gives daily kWh. Multiply by 30 for the month, then by your rate. The table assumes a rate of $0.15/kWh so you can compare appliances at a glance. Swap in your own rate to see how the numbers scale.
| Appliance | Wattage | Hours/day | kWh/month | Cost/month |
|---|---|---|---|---|
| Central air conditioner | 3,500 | 8 | 840 | $126.00 |
| Electric water heater | 4,000 | 3 | 360 | $54.00 |
| Electric clothes dryer | 3,000 | 1 | 90 | $13.50 |
| Refrigerator (cycling avg) | 150 | 24 | 108 | $16.20 |
| Dishwasher | 1,800 | 1 | 54 | $8.10 |
| Gaming PC | 500 | 4 | 60 | $9.00 |
| 55-inch LED TV | 100 | 5 | 15 | $2.25 |
| Microwave oven | 1,000 | 0.5 | 15 | $2.25 |
| WiFi router | 10 | 24 | 7.2 | $1.08 |
| LED bulb (single) | 9 | 6 | 1.6 | $0.24 |
Worked example: a 2-bedroom apartment
Take a household running five things: a 1.5-ton AC (1,500W) for 8 hours, a fridge (150W) for 24 hours, an electric water heater (4,000W) for 2 hours, four LED bulbs (36W total) for 6 hours, and a 55-inch TV (100W) for 5 hours. The daily kWh work out to 12, 3.6, 8, 0.22, and 0.5 respectively, a total of 24.32 kWh per day. Over 30 days that is about 730 kWh. At $0.15/kWh the energy portion is roughly $109.50.
Your actual bill will land higher than that, and this is where people get confused. Utilities add a fixed monthly service charge (commonly $8 to $15) plus per-kWh delivery or distribution fees that are billed separately from the energy supply rate. Add a $12 service charge and a $0.05/kWh delivery fee (another $36.50 on 730 kWh) and the same usage now costs about $158. That gap between usage times rate and the printed total is normal, so read your bill for both the supply rate and the delivery rate before you trust a single number.
Rates vary a lot by region
| Region | Typical residential rate |
|---|---|
| US average | $0.16 / kWh |
| Hawaii (highest US) | $0.33 / kWh |
| Louisiana (low US) | $0.10 / kWh |
| United Kingdom | ≈ £0.25 / kWh |
| Australia | ≈ AU$0.30 / kWh |
| India | ≈ ₹6–8 / unit |
Flat-rate plans charge the same price around the clock. Time-of-use plans split the day into peak and off-peak windows where the peak price can be two to three times the off-peak one. Shifting the dryer, dishwasher, or EV charging to a late-night off-peak window only saves money if you are actually on a time-of-use tariff. On a flat rate the time of day makes no difference at all.
What phantom loads really cost
Devices left plugged in keep drawing a trickle of power even when switched off. Individually the watts are tiny, but they run every hour of the year. The yearly figures below assume the standby wattage runs continuously at a $0.15/kWh rate.
| Device | Standby watts | Yearly cost |
|---|---|---|
| Television (standby) | 2–5 | $3–7 |
| Game console (rest mode) | 10–15 | $14–21 |
| Cable / set-top box | 15–25 | $21–35 |
| Desktop PC (sleep) | 3–5 | $4–7 |
| Microwave clock display | 1–3 | $1–4 |