Electricity Cost Calculator

Your electricity bill is the sum of every appliance running in your home. But most people have no idea which devices cost the most — or which small changes would actually make a dent in the number at the bottom of the bill.

This calculator tells you exactly what any appliance costs to run: enter the wattage, how many hours a day you use it, and your electricity unit rate, and you'll get the cost per day, month, and year.

How Much Does It Cost to Run Common Appliances?

The table below uses a UK rate of 24p/kWh and US rate of 16¢/kWh (2025–2026 averages).

Appliance	Wattage	Hours/day	Cost/month (UK)	Cost/month (US)
Electric shower (9.5kW)	9,500W	0.2 hrs	£13.68	$9.12
Tumble dryer	2,500W	1 hr	£18.00	$12.00
Electric oven	2,200W	1 hr	£15.84	$10.56
Dishwasher	1,800W	1 hr	£12.96	$8.64
Washing machine	1,200W	1 hr	£8.64	$5.76
Electric heater (fan)	2,000W	4 hrs	£57.60	$38.40
Fridge-freezer	150W	24 hrs	£25.92	$17.28
LED TV (55 inch)	90W	4 hrs	£2.59	$1.73
LED bulb (per bulb)	10W	5 hrs	£0.36	$0.24
Desktop PC + monitor	300W	8 hrs	£17.28	$11.52
EV charger (7kW home)	7,000W	3 hrs	£151.20	$100.80
Air conditioning unit	1,500W	6 hrs	£64.80	$43.20

Electric heating and EV charging are the two biggest drivers of electricity bills in modern homes. A single electric heater running 4 hours a day adds nearly £58/month in the UK.

The Formula

Cost = (Wattage ÷ 1,000) × Hours used × Unit rate × Days

• Wattage ÷ 1,000 converts watts to kilowatts
• Multiply by hours of daily use to get kWh per day
• Multiply by your unit rate (in £/kWh or $/kWh)
• Multiply by number of days for monthly or annual totals

Example — running a tumble dryer:

• Wattage: 2,500W
• Daily use: 1 hour
• UK unit rate: £0.24/kWh

(2,500 ÷ 1,000) × 1 × £0.24 = £0.60 per use
£0.60 × 30 = £18.00 per month
£0.60 × 365 = £219 per year

Two loads per day instead of one doubles this to £438/year just for drying clothes.

Where to Find Your Electricity Unit Rate

UK: Your unit rate (price per kWh) is on your electricity bill under "unit rate" or "standing charges" section. If you're on a standard variable tariff, check the Ofgem price cap rate — around 24p/kWh as of mid-2025. Smart meters show real-time costs in your app.

US: Find your rate in ¢/kWh on your utility bill. The national average is around 16¢/kWh, but rates vary significantly: California averages 26¢/kWh, Louisiana around 10¢/kWh. Check your state's EIA figures for accuracy.

EU: EU rates vary from 10¢/kWh (Bulgaria) to 45¢/kWh (Germany and Denmark). Check your supplier's website or your latest bill.

The 10 Highest Running Cost Appliances in Most Homes

1. Electric water heater / immersion — if on constantly: £80–£130/month (UK)
2. Storage heaters / night storage units — £50–£120/month per unit
3. Air conditioning — £50–£90/month when running daily
4. Tumble dryer — £15–£30/month (daily use)
5. Fridge-freezer — runs 24/7, £20–£30/month
6. Dishwasher — £8–£15/month
7. Electric oven — £12–£20/month (once daily)
8. Washing machine — £6–£12/month
9. Games console + TV — £10–£20/month (heavy use)
10. Desktop PC — £12–£20/month (all-day use)

Note: Gas central heating is NOT on this list because it doesn't appear on your electricity bill. If you've recently switched to a heat pump, your electricity consumption may have risen significantly.

How to Reduce Your Electricity Bill

Biggest single impact:

• Switch to a better tariff — compare at Uswitch (UK), Power to Choose (Texas), or your state energy regulator
• Install a smart meter to identify high-usage periods
• Shift high-energy appliance use (washing machine, dishwasher) to off-peak hours if you're on a time-of-use tariff

Medium impact:

• Replace a tumble dryer with a heat pump dryer — cuts energy use by 50–60%
• Upgrade fridge-freezer to A++ rated (old D-rated units use 3× more energy)
• Use an air fryer instead of oven for small meals (90% less energy)

Lower impact but adds up:

• Switch all bulbs to LED if you haven't already — a 60W incandescent costs £26/year; an 8W LED replacement costs £3.50/year
• Unplug phone chargers and TVs from standby — each device costs £1–£5/year individually, but multiplied across 10–20 devices it adds up
• Use a smart plug timer on the kettle, coffee machine, and other always-on appliances

Related Calculators

• Solar Panel Calculator — see if solar could offset your electricity costs
• EV Charging Time Calculator — calculate the cost of charging your electric vehicle
• Amps to Watts Converter — convert between electrical units for the calculator above
• Battery Life Calculator — estimate how long a battery will power a device

FAQs

How do I find the wattage of an appliance?

Check the label on the back or bottom of the appliance — it's usually listed as "W" or "watts". If you can't find it, search "[appliance brand and model] wattage" or use a smart plug with energy monitoring (like TP-Link Kasa or Shelly) to measure it directly.

What is a kWh?

A kilowatt-hour (kWh) is the standard unit your electricity bill uses. It equals running a 1,000W appliance for 1 hour. A 100W light bulb running for 10 hours uses 1 kWh. Your electricity supplier charges you per kWh.

Why has my electricity bill gone up so much?

The most common causes are: a new appliance (especially EV charger, heat pump, or air conditioning), higher unit rates from your supplier, or changes in daily usage habits (more time at home, new baby, home office). Use this calculator to identify which appliance category has the biggest impact.

Does leaving devices on standby really matter?

A single device on standby uses a small amount (typically 0.5–5W), but a home with 20 devices on standby 24/7 adds up to 100W+ running constantly — that's around £210/year at 24p/kWh. A smart power strip with master socket can eliminate this automatically.

What's the most energy-efficient way to cook?

For small meals: microwave uses 30–50% less energy than an oven. Air fryer uses 70–90% less energy. Induction hob is 80% efficient vs 40% for gas (though gas costs less per unit currently). Slow cooker uses less energy than an oven for longer cooking, despite the longer run time.