Question 1

How do I calculate the electricity cost of an appliance?

Accepted Answer

Cost = (Watts × Hours used ÷ 1000) × price per kWh. This gives the energy used in kilowatt-hours (kWh), which is then multiplied by your electricity rate. Example: a 1,000 W space heater run for 4 hours/day at $0.16/kWh costs (1000 × 4 ÷ 1000) × 0.16 = 4 kWh × $0.16 = $0.64/day, or about $19.20/month.

Question 2

Where do I find the wattage of my appliance?

Accepted Answer

Check the label on the appliance itself, its power adapter/brick, or the user manual — wattage (W) is usually printed directly. If only amps (A) and voltage (V) are given, multiply them: Watts = Amps × Volts (e.g. a device drawing 5A at 120V uses 600W). Smart plugs with energy monitoring can also measure actual real-world wattage, which is often lower than the "maximum rated" wattage on the label.

Question 3

Where do I find my electricity rate ($/kWh)?

Accepted Answer

Your electricity rate is listed on your utility bill, usually expressed in cents or dollars per kilowatt-hour (¢/kWh or $/kWh). Rates vary significantly by region, time of day (some utilities charge more during peak hours), and season. US average residential rates are roughly $0.12–$0.30/kWh depending on the state; if your bill includes multiple charges (energy, delivery, taxes), add them together and divide by your total kWh used for an accurate all-in rate.

Question 4

Which household appliances cost the most to run?

Accepted Answer

High-wattage appliances used for long periods cost the most: electric water heaters (3,000–4,500 W), central air conditioning (3,000–5,000 W), electric clothes dryers (2,000–3,000 W), and space heaters (1,500 W) are typically the biggest contributors to a power bill. Lower-wattage devices like LED bulbs (5–10 W), phone chargers (5–10 W), and routers (10–20 W) cost only a few cents per month even running continuously, since cost depends on both wattage and total hours of use.

Question 5

How can I reduce my electricity costs?

Accepted Answer

The biggest savings usually come from reducing the runtime of high-wattage devices (efficient thermostat scheduling, washing clothes in cold water, air-drying instead of using a dryer), switching to more efficient models (LED bulbs use ~75% less energy than incandescent; modern fridges use far less than units from 10+ years ago), and being mindful of "always-on" standby power draw from electronics, which can add up to 5–10% of a typical bill.

Electricity Cost Calculator

Everyday Uses

Appliance running costs

Upgrade payback

Always-on devices

Bill detective work

Time-of-use tariffs

Standby draw across a whole house

Frequently Asked Questions

How do I calculate the electricity cost of an appliance?

Where do I find the wattage of my appliance?

Where do I find my electricity rate ($/kWh)?

Which household appliances cost the most to run?

How can I reduce my electricity costs?

Related Calculators

Everyday Uses

Appliance running costs

Upgrade payback

Always-on devices

Bill detective work

Time-of-use tariffs

Standby draw across a whole house

Frequently Asked Questions

How do I calculate the electricity cost of an appliance?

Where do I find the wattage of my appliance?

Where do I find my electricity rate ($/kWh)?

Which household appliances cost the most to run?

How can I reduce my electricity costs?