Money

Electricity Cost Calculator | Estimate Monthly Bill by Appliance

Enter each appliance's wattage, usage time, and electricity rate to estimate your monthly electricity bill. Add multiple appliances and see the total cost at a glance.

per kWh
Appliance Wattage (W) Hours/day Days/month Monthly usage Monthly cost
[[ fmtKwh(rowResults[i]?.kwhPerMonth) ]] [[ fmtYen(rowResults[i]?.costPerMonth) ]] yen
Total [[ fmtKwh(total.kwhPerMonth) ]] [[ fmtYen(total.costPerMonth) ]] yen

Typical Appliance Power Usage & Cost (at 31 yen/kWh)

Appliance Typical wattage Estimated cost per hour
Air Conditioner (Cooling) 800 W 25 yen
Air Conditioner (Heating) 1,200 W 37 yen
Refrigerator 150 W 5 yen
Washer-Dryer 1,200 W 37 yen
Microwave Oven 600 W 19 yen
IH Cooktop 1,400 W 43 yen
Rice Cooker (while cooking) 700 W 22 yen
Hair Dryer 1,200 W 37 yen
TV (40-inch LCD) 150 W 5 yen
Desktop PC 150 W 5 yen
LED Light (1 fixture) 10 W 0 yen
Electric Kettle 1,300 W 40 yen

Wattage figures are typical estimates for common models. Actual power consumption varies by model, settings, and usage conditions. Check the product's rated power consumption for exact values.

Tips

  • Electricity rates vary by utility company, plan, and region. Enter the rate shown on your latest billing statement for a more accurate estimate.
  • Air conditioner power draw fluctuates a lot with the set temperature and outdoor temperature, so treat this calculation as an average estimate only.
  • Add multiple appliances to see your household's estimated total monthly electricity cost in the total row.
  • Standby power (drawn just by being plugged in) can add up over time, so it's worth using a switched power strip to fully cut power to unused appliances.

Frequently Asked Questions

Check the billing statement from your utility company or the pricing page on their website or app. Most tiered plans charge a higher rate as usage increases.

Yes. Enter the standby wattage in the "Wattage" field and 24 in the "Hours/day" field to estimate the monthly cost of power drawn while an appliance is idle.

An air conditioner's power draw depends heavily on the set temperature, the difference between indoor and outdoor temperature, room size, and the unit's energy efficiency. Power draw tends to be highest right after startup, while it works to reach the target temperature.

This tool estimates cost based solely on appliance power consumption. Actual bills also include a base charge, fuel cost adjustments, and renewable energy surcharges, so the totals will differ.
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Side Note — The Surprising Ranking of Costly Home Appliances

When people think of a high electricity bill, air conditioners are usually the first suspect. But since a refrigerator runs continuously all year round, its annual energy consumption can rival that of an air conditioner. Because it's "always on," its instantaneous wattage is small, yet the monthly and yearly total becomes surprisingly significant.

On the other hand, appliances like electric kettles and hair dryers draw a very high instantaneous wattage (1,200–1,400W class), but because they're only used for short bursts, their impact on the monthly bill is often smaller than expected. Understanding your real electricity usage requires multiplying wattage by both usage time and frequency, not just looking at the wattage number alone.

Many utility companies now offer time-of-use plans with rates that vary by time of day. Running short, high-wattage appliances like kettles or washer-dryers during off-peak hours can lower your bill for the same amount of usage. Try adjusting the rate in this tool to explore how different plans might affect your total.

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