Where do I find the wattage of my appliances?

Check the label on the back or bottom of the device, or its user manual. It is usually listed as "W" or "Watts." For variable-power devices like inverter ACs, use the average operating wattage.

Where do I find my electricity rate?

Your electricity rate (in $/kWh) appears on your utility bill. Rates vary by country and provider but typically range from $0.08 to $0.40 per kWh.

Why does monthly cost use 30.44 days?

A calendar month averages 30.44 days (365 / 12), which gives a more accurate monthly figure than using exactly 30 days.

How is kWh consumption calculated?

kWh per day = (wattage / 1000) × hours of use. For example, a 1,500 W heater running 4 hours uses (1500 / 1000) × 4 = 6 kWh per day.

Can I use a different rate for each appliance?

Yes — each appliance row uses the rate you entered when adding it. This lets you model time-of-use pricing where appliances run during peak or off-peak periods.

Does this include standby power?

Only if you add it manually. Create a separate entry for the standby wattage of a device set to run 24 hours per day to capture idle consumption.

Power Bill Estimator

Name: Power Bill Estimator
Availability: InStock
Author: Nham Vu

Add multiple appliances with their wattage, daily usage hours, and electricity rate to estimate your total monthly electricity bill.

Add an Appliance

Appliance Name (optional)

Wattage (W)

Check the label or manual of the device.

Daily Usage (hours/day)

Electricity Rate ($/kWh)

Find this on your electricity bill.

Common Appliances

Add appliances on the left to estimate your monthly power bill.

Done!

Summary

Add multiple appliances with their wattage, daily usage hours, and electricity rate to estimate your total monthly electricity bill.

How it works

Enter an appliance name, its wattage (W), and daily usage hours.
Set your electricity rate in $/kWh — find this on your utility bill.
Click "Add Appliance" to add it to the list.
The tool computes kWh/day = (watts / 1000) × hours, then multiplies by rate for daily cost.
Monthly cost uses 30.44 days (365 / 12). All appliances are summed into a grand total.
A usage bar shows each appliance's share of the total bill.

Use cases

Estimate the full monthly electricity bill before it arrives.
Identify which appliances consume the most power.
Compare the impact of replacing old appliances with energy-efficient models.
Plan energy budgets for a new home, apartment, or small office.
Model cost savings from reducing usage hours on high-wattage devices.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu