๐ก Electricity Bill Calculator
This does not include base service fees or fuel cost adjustments โ treat it as an estimate only.
Enter an appliance's power consumption (watts), how many hours a day and days a month you use it, and your electricity rate (currency per kWh) to estimate what running it costs. Check your utility bill or provider's rate plan for the rate to enter.
How to use
- Enter the appliance's power consumption in watts (usually printed on the label or in the manual).
- Enter how many hours per day and days per month you use it.
- Enter your electricity rate (per kWh) โ the estimated cost is calculated automatically.
How the calculation works
This tool estimates the electricity cost of an appliance from its power draw and how long you use it. Daily energy (kWh) = power (W) รท 1000 ร hours per day Monthly energy (kWh) = daily energy ร days used per month Cost = energy (kWh) ร price per kWh The default of ยฅ31/kWh is the reference rate that Japan's appliance industry fair-trade council uses for electricity cost labels on appliances (revised in 2022). Your actual rate depends on your supplier, plan and usage tier. One kWh is the energy used by a 1000 W appliance running for one hour.
Worked example
A 1,200 W hair dryer used 2 hours a day, 30 days a month Daily energy: 1.2 kW ร 2 h = 2.4 kWh Monthly energy: 2.4 ร 30 = 72 kWh Cost: 72 ร ยฅ31 = ยฅ2,232 a month (about ยฅ74 a day, about ยฅ26,784 a year) A 10 W LED bulb used 5 hours a day for 30 days 0.01 kW ร 5 ร 30 = 1.5 kWh โ about ยฅ47 a month
Things to be aware of
- Air conditioners and fridges draw very different amounts of power depending on how hard they are working. Using the maximum rated power overstates the cost.
- Real bills also include a basic charge, fuel cost adjustments and renewable energy surcharges.
- Standby power (used while an appliance is off) can add up over 24 hours a day.
FAQ
Where do I find my electricity rate?
Check your utility bill or your electricity provider's rate plan page. If your plan has tiered pricing, use an average rate for a rough estimate.
Where do I find an appliance's wattage?
Most appliances list their rated power consumption (in watts) on a label on the back or bottom of the unit, or in the manual.
Does this include the base monthly service fee?
No. This tool only calculates the usage-based cost of running a specific appliance. Your actual bill will also include a base service fee and other charges like fuel cost adjustments.