Cost Calculators

Appliance energy cost estimation

Direct answer

Convert watts to kilowatts, multiply by actual run time, then multiply by the local price per kWh.

energyElectricity Cost Calculatorhousehold cost
Region
The formula is universal; appliance labels, tariffs, currency, and operating patterns differ.
Best calculator
Electricity Cost Calculator
Reviewed
2026-07-14

Reproducible workflow

Method, inputs, and worked result

Method

  1. 1Use measured average wattage when possible.
  2. 2Calculate watts x hours / 1,000.
  3. 3Multiply kWh by rate and separate standby use.

Inputs used

  • 1,200 W heater
  • 3 hours daily for 30 days
  • $0.18 per kWh

Worked example

A portable heater runs three hours daily for 30 days.

  1. 1.1,200 W is 1.2 kW.
  2. 2.1.2 x 3 x 30 = 108 kWh.
  3. 3.108 x $0.18 = $19.44.

108 kWh and $19.44 for the month.

Reproduce: Log representative hours, rerun the formula, and compare with a plug-in meter.

Copy-ready note

Planning summary to paste into a task, invoice, or message

Open Electricity Cost Calculator
Scenario: Appliance energy cost estimation
Direct answer: Convert watts to kilowatts, multiply by actual run time, then multiply by the local price per kWh.
Region: The formula is universal; appliance labels, tariffs, currency, and operating patterns differ.
Inputs: 1,200 W heater; 3 hours daily for 30 days; $0.18 per kWh
Method: Use measured average wattage when possible. Calculate watts x hours / 1,000. Multiply kWh by rate and separate standby use.
Example result: 108 kWh and $19.44 for the month.
Reproduce: Log representative hours, rerun the formula, and compare with a plug-in meter.
Boundary: Cycling devices need representative meter data; a nameplate-only estimate is an upper-bound proxy.
Next step: open Electricity Cost Calculator from Cost Calculators.

Common use cases

space heater review

computer runtime

kitchen appliance check

What can change the result

Thermostat cycling

Standby consumption

Peak and off-peak rates

Mistakes to avoid

  • Using maximum watts as continuous draw
  • Forgetting to divide by 1,000
  • Assigning whole-home kWh to one device

Questions to explore next

  • Rated or measured watts?
  • How much does standby add?
  • How do I estimate cycling appliances?