Result
$21.90 per month
1500 watts for 3 hours per day costs about $0.72 per day at $0.16/kWh.
- Daily cost
- $0.72
- Monthly cost
- $21.90
- Yearly cost
- $262.80
- Daily usage
- 4.5 kWh
Estimate only. Verify wattage, utility rates, equipment ratings, and safety requirements before relying on this cost. Read the full disclaimer.
Quick answer
Quick answer
With the sample inputs, this calculator returns $21.90 per month. Daily cost: $0.72. The result is an estimated operating cost from the wattage, run time, and rate you enter. Use your all-in kWh rate if you want it to line up more closely with a bill.
Publisher
Published by EverydayCalc Editorial
Our calculator pages are built to show the formula, explain the inputs, provide examples, and highlight assumptions so readers can understand how each result is estimated.
Results are estimates based on the inputs provided and the assumptions shown on this page. For financial, tax, legal, medical, or other high-stakes decisions, verify results with a qualified professional or official source.
How to use this calculator
Start with device wattage, divide by 1,000 to get kilowatts, multiply by hours used per day, then multiply by your electricity rate. The result shows daily kWh and cost, then scales the same estimate to a month and year.
Where to find your all-in kWh rate
Your electric bill may list energy, delivery, riders, taxes, or other usage-based charges separately. For a realistic bill estimate, divide those usage-based charges by billed kWh or use the all-in rate shown on the bill.
When to adjust wattage or runtime
Nameplate watts can overstate cost for devices that cycle, such as refrigerators, AC units, dehumidifiers, and heaters with thermostats. If you know the duty cycle or measured kWh, use a more specific appliance calculator or a plug-in power meter reading.
When to use this calculator
- Estimating monthly or yearly energy cost
- Testing watts, runtime, rate, and duty cycle changes
- Comparing efficient alternatives before buying or changing use
Tips for better estimates
- Use measured watts when possible, especially for appliances that cycle on and off.
- Enter the all-in local electricity rate from a recent bill.
- Rerun the estimate for seasonal use, lower runtime, or a more efficient alternative.
How this calculator is reviewed
This page is checked for inputs, formulas, examples, assumptions, topic fit, and related links. For this calculator, the review also covers watts, hours used, local electricity rate, duty cycle, seasonal use, and efficient alternatives.
The sample result is covered by automated tests, and the page links to supporting guides so readers can check the assumptions before acting. This review note is current for May 2026. If a formula, label, or assumption looks off, send the page URL and your inputs through the contact page.
Formula and methodology
Cost = energy used or fuel consumed multiplied by your rate, adjusted for runtime, efficiency, or usage period.
Assumptions to check
The key inputs are Power draw, Use per day, Use state average rate, Electricity rate. Confirm watts, hours used, local electricity rate, duty cycle, seasonal use, and efficient alternatives before relying on the cost.
How this estimate was built
This page converts watts to kilowatts, multiplies by daily runtime and kWh rate, then scales the result to daily, monthly, and yearly cost using a year-average month.
Worked example
Example inputs: Power draw: 1500 watts; Use per day: 3 hours; Use state average rate: 0.16; Electricity rate: $0.16 /kWh. With those values, the calculator returns $21.90 per month. 1500 watts for 3 hours per day costs about $0.72 per day at $0.16/kWh.
Common appliance wattage and estimated electricity cost
| Space heater | 1,500 watts; about $21.90/month at 3 hours/day and $0.16/kWh |
|---|---|
| Gaming PC | 400 watts; about $9.73/month at 5 hours/day and $0.16/kWh |
| Refrigerator | 150 to 800 watts while running; actual monthly cost depends on cycling and efficiency |
| Window AC | 900 watts; about $35.04/month at 8 hours/day and $0.16/kWh |
| LED light bulb | 9 to 12 watts; usually low per bulb, but many bulbs and long hours add up |
Example scenarios
- A 1500 watt space heater used 3 hours per day at $0.16/kWh costs about $0.72 per day, $21.90 per month, and $262.80 per year.
- A device that uses 4.5 kWh in a day costs about $0.72 at $0.16/kWh, or about $21.90 for a 30.4167-day average month.
- A gaming PC drawing 400 watts for 5 hours per day at $0.16/kWh costs about $0.32 per day and $9.73 per month.
- A refrigerator may show a high running wattage, but the compressor cycles on and off, so measured kWh is better than assuming full power all day.
- A window AC drawing 900 watts for 8 hours per day at $0.16/kWh costs about $1.15 per day and $35.04 per month.
Quick reference chart
| Sample result | $21.90 per month |
|---|---|
| Daily cost | $0.72 |
| Monthly cost | $21.90 |
| Yearly cost | $262.80 |
| Daily usage | 4.5 kWh |
| Best next step | Use this estimate with the real watts, hours used, local electricity rate, duty cycle, and seasonal use. Compare efficient alternatives if the monthly or yearly cost is higher than expected. |
FAQs
Electricity Cost Calculator questions
How much does electricity cost per kWh?
Electricity rates vary by location, plan, season, and bill structure. Use the all-in kWh rate from a recent bill when possible, including delivery charges and usage-based fees.
How do you calculate electricity cost?
Convert watts to kilowatts by dividing by 1,000, multiply by hours used, then multiply by your electricity rate. For monthly cost, multiply the daily cost by about 30.4167 days.
How much does a 1500 watt heater cost to run?
A 1500 watt heater uses 1.5 kWh per hour. At $0.16 per kWh, it costs about $0.24 per hour, $0.72 for 3 hours, and about $21.90 per month if used 3 hours every day.
What appliances use the most electricity?
Heating, cooling, water heating, dryers, ovens, pool pumps, hot tubs, and large always-on equipment often use the most electricity because they draw many watts or run for long periods.
How can I lower electricity usage?
Lower runtime, choose efficient equipment, reduce standby loads, use thermostats or timers, maintain filters and coils, shift flexible use to off-peak hours if available, and compare actual watts with a plug-in power meter.
Does wattage always stay the same?
Some appliances cycle on and off. For those, the result is an estimate unless you measure actual usage with a power meter.
Common planning mistakes
Using nameplate watts when actual draw is lower, ignoring duty cycle, using the advertised rate instead of the all-in local rate, and assuming seasonal use stays the same all year.
Cite or embed this calculator
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