Electronics

Power Consumption Calculator

Calculate how much electricity your devices use and what it costs. Add multiple devices to see total daily, monthly, and yearly consumption.

Quick Answer

kWh = Watts × Hours / 1000. A 100W device running 6 hours/day uses 0.6 kWh/day or 18 kWh/month. At $0.16/kWh, that costs about $2.88/month.

Devices

Name

Watts

Hrs/Day

Qty

Electricity Rate ($/kWh)

US average: $0.16/kWh

Results

4.20 kWh

Daily / $0.67

126.0 kWh

Monthly / $20.16

1533 kWh

Yearly / $245.28

Device	Daily kWh	Monthly Cost
LED TV	0.60	$2.88
Refrigerator	3.60	$17.28

About This Tool

The Power Consumption Calculator helps you understand how much electricity your appliances and devices use and what that costs. By entering the wattage, daily usage hours, and your electricity rate, you can identify which devices are the biggest energy consumers and make informed decisions about energy efficiency.

Understanding Kilowatt-Hours

A kilowatt-hour (kWh) is the standard unit of energy used by electric utilities for billing. One kWh equals 1,000 watts of power used for one hour. A 100-watt light bulb running for 10 hours uses exactly 1 kWh. Your electricity bill charges per kWh consumed, so reducing either wattage or usage time directly reduces your bill.

Finding Device Wattage

Check the label on the device or its power adapter, which usually lists wattage or amps and volts (multiply them to get watts). You can also use a plug-in power meter like a Kill-A-Watt to measure actual consumption. Many devices use less than their rated wattage during normal operation because the label shows maximum draw.

Average Electricity Costs

The US national average is about $0.16 per kWh as of 2025, but rates vary dramatically. Hawaii averages over $0.40/kWh while Louisiana averages around $0.10/kWh. Some utilities charge different rates for peak and off-peak hours, or increase the rate as you use more (tiered pricing). Check your latest utility bill for your actual rate.

Biggest Energy Users

Air conditioning, water heaters, and electric dryers are typically the largest residential energy consumers. HVAC systems alone can account for 40-60% of a home electricity bill. Refrigerators run 24/7 but modern ones are quite efficient at 100-200 kWh per year. Electronics in standby mode (phantom loads) collectively waste 5-10% of residential electricity.

Frequently Asked Questions

What is the average electricity cost in the US?

The national average is approximately $0.16 per kWh as of 2025. Your rate depends on your state and utility company. Check your electricity bill for the exact rate, which may include time-of-use pricing or tiered rates that change with consumption.

How do I find the wattage of my device?

Look for a label on the device or its power adapter listing watts (W) or amps (A) and volts (V). Multiply amps by volts to get watts. For more accurate readings, use a plug-in power meter. Many devices draw less than their rated maximum during normal use.

Do devices use electricity when turned off?

Many modern electronics consume standby power (phantom load) even when turned off. TVs, game consoles, phone chargers, and computers in sleep mode all draw a few watts continuously. This can add up to 5-10% of your electricity bill. Use smart power strips to eliminate phantom loads.

How much does it cost to run a space heater?

A typical 1,500W space heater running 8 hours per day uses 12 kWh daily. At $0.16/kWh, that costs about $1.92/day or $57.60/month. Electric heating is one of the most expensive ways to heat a space compared to gas or heat pumps.

What uses the most electricity in a home?

HVAC (heating, ventilation, air conditioning) is the biggest consumer, accounting for 40-60% of residential electricity use. Water heaters, clothes dryers, ovens, and refrigerators are next. Lighting and electronics have become much more efficient but still contribute significantly in aggregate.

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