Daily, monthly, and yearly cost
Best starting point when you have wattage, average hours per day, and your electricity rate.
Open appliance cost calculatorElectricity cost calculators
Electricity Cost Calculators
Choose by the number you already trust: watts and hours, measured kWh, an hourly comparison, or a rate from your bill. If the input is uncertain, use a guide before treating the result as useful.
Choose by task
Which electricity calculator should you use?
Start with the strongest input you have. These cards point to the calculator for that input; the lower sections explain when a guide should come first.
Watts into kWh
Start here when a label or product page gives watts but you need energy use over a number of hours.
Open watts to kWh calculatorOne-hour running cost
Good for short-session appliance comparisons, one-hour checks, or a quick usage-cost comparison.
Open hourly cost calculatorKnown kWh into cost
Choose this if a bill, meter, smart plug, or estimate already gives you kWh.
Open kWh to cost calculatorBefore choosing
The basic path from wattage to cost
Most appliance electricity estimates start with wattage. Watts describe power while the device is running. Electricity bills usually charge by kWh, so the missing step is runtime: watts multiplied by hours, divided by 1000, gives kWh.
After that, multiply kWh by your electricity rate. For a repeating habit, such as running a fan every night or a dehumidifier every afternoon, daily cost is usually more useful than a single-hour figure. For a step-by-step walkthrough, read how to calculate electricity cost from watts.
- Find the wattage from the appliance label, manual, or product page.
- Estimate a realistic runtime instead of the longest possible runtime.
- Use your own electricity rate per kWh so the estimate follows the currency you used for the rate.
Calculator selection
Start from the number you trust most
Pick the path that matches your strongest input. A label wattage, a measured kWh value, and a bill line item can all lead to useful estimates, but they should not be interpreted the same way.
| If your best input is... | Start here | Why |
|---|---|---|
| Watts, hours per day, rate per kWh | Appliance Electricity Cost Calculator | Good when you are estimating from a label and runtime. |
| Watts and runtime | Watts to kWh Calculator | Good when you want energy use before thinking about price. |
| Measured kWh and rate | kWh to Cost Calculator | Good when a meter or smart plug already measured energy use. |
| A bill line item | Read the bill-input guide first | Good when you are unsure which bill number belongs in a calculator. |
| Watts and rate for a one-hour comparison | Electricity Cost Per Hour Calculator | One-hour, 8-hour, and 24-hour running-cost checks. |
| A real-life setup | Home Office or appliance examples | Good when you want an example scenario before entering numbers. |
Input guide
Watts vs kWh
Learn why watts alone cannot tell you electricity cost, and how kWh connects appliance labels to utility bills.
Read the guideInput guide
How to find appliance wattage
Check where to find wattage, what to do when a label lists amps, and when measured wattage is more useful.
Read the guideFormula guide
Calculate cost from watts
See the full path from wattage and runtime to kWh, then from kWh to estimated cost.
Read the guideBill input
Find your rate per kWh
Learn where to find the electricity rate to enter in the cost calculators.
Read the guideBill check
Why a bill can be higher than the calculator estimate
Learn why taxes, fixed fees, rate rules, and changing runtime can push the real bill above a simple estimate.
Read the guideFAQ
Common questions
Do these calculators show my full utility bill?
No. They estimate usage-based cost from wattage, runtime, quantity, and rate. Real bills can also include fixed fees, taxes, tiered rates, and seasonal changes.
Which calculator should I use first?
If you already know wattage, hours per day, and rate, start with the appliance electricity cost calculator. If you only want energy use, start with the watts to kWh calculator.
Can I use the same rate for every appliance?
For a rough estimate, yes, if the same rate applies when the appliance runs. If your utility uses tiered or time-of-use pricing, choose the rate that best matches when the appliance runs.