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Electricity Running Cost Calculator

Calculate how much it costs to run any electrical appliance

Reference Info & Formulas
Formula

Running Cost

Cost = (W / 1000) x hours x rate

Daily kWh

kWh = (W / 1000) x hours/day

Typical Wattages

100W: LED TV

500W: Washing machine

2000W: Storage heater

3000W: Kettle / Immersion

7000W: EV charger (7kW)

8500W: Electric shower

Appliance Details
Enter appliance power and usage
W
hrs
p/kWh
p/day

Data: Ofgem price cap rates (January 2025)

For guidance only. The responsibility for any electrical installation lies with the qualified person carrying out the work. Always verify calculations independently and apply professional judgement.

How Electricity Running Costs Are Calculated

The cost to run any electrical appliance depends on its power rating, how long you use it, and your electricity tariff.

The basic formula multiplies the appliance wattage (converted to kilowatts) by the number of hours used and the unit rate in pence per kilowatt-hour (kWh).

Cost (pence) = (W / 1000) x hours x rate (p/kWh)
W
= Appliance power rating in watts
hours
= Duration of use
rate
= Electricity unit rate in pence per kWh

Ofgem price cap (January 2025): 24.50p/kWh

For example, running a 2kW fan heater for 4 hours costs: (2000 / 1000) x 4 x 24.5 = 196p, or 1.96 pounds per session. Over a month, that adds up to nearly 59 pounds if used daily.

Common Appliance Running Costs

Typical daily running costs at 24.5p/kWh

Based on Ofgem January 2025 price cap
AppliancePower (W)Typical UseDaily Cost
LED TV1004 hrs/day9.8p
Washing Machine5001 hr/day12.3p
Dishwasher1,8001 hr/day44.1p
Tumble Dryer2,5001 hr/day61.3p
Oven2,5001 hr/day61.3p
Kettle3,00010 mins/day12.3p
Immersion Heater3,0003 hrs/day220.5p
Storage Heater2,0007 hrs/day343.0p
EV Charger (7kW)7,0003 hrs/day514.5p
Electric Shower8,50010 mins/day34.7p

Actual costs vary with tariff, appliance efficiency, and usage patterns.

Tips for Reducing Electricity Bills

Switch to Off-Peak Tariffs

If you have an EV charger, immersion heater, or storage heaters, a time-of-use tariff (such as Economy 7 or Octopus Go) can cut costs dramatically. Off-peak rates can be as low as 7-10p/kWh compared to the standard 24.5p rate.

Monitor with a Smart Meter

Smart meters with in-home displays let you see real-time consumption in pounds and pence. Studies show that households with smart meters reduce electricity use by 2-4% simply by being aware of what costs the most.

Standing Charge Applies Regardless

Even if you use zero electricity, the standing charge still applies. At 46.36p/day, that is roughly 169 pounds per year before you switch anything on. Some suppliers offer tariffs with no standing charge but at a higher unit rate — compare total costs before switching.

Frequently Asked Questions

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