Electricity Bill Calculator — Calculate Your Energy Costs Per Appliance
With electricity prices significantly higher than in past decades, understanding exactly how much each appliance costs to run lets you make informed decisions about usage, identify the biggest cost drivers, and estimate savings from efficiency improvements. The free electricity cost calculator on PublicSoftTools computes daily, monthly, and annual running costs for any appliance based on its wattage, usage hours, and your local electricity price.
The Electricity Cost Formula
Electricity consumption is measured in kilowatt-hours (kWh). One kWh is the energy used by a 1,000-watt (1 kW) appliance running for 1 hour.
Daily energy use (kWh) = (Wattage × Daily hours of use) / 1,000
Daily cost = Daily kWh × Price per kWh
Example: A 2,000-watt electric oven used for 1.5 hours/day at 28p/kWh: Energy = (2,000 × 1.5) / 1,000 = 3 kWh/day. Daily cost = 3 × £0.28 = £0.84. Monthly: £0.84 × 30 = £25.20. Annual: £0.84 × 365 = £306.60.
How to Use the Electricity Bill Calculator
- Open the electricity bill calculator.
- Enter the appliance wattage (W or kW). Check the appliance label, manual, or the product specifications page. For appliances with variable consumption (like fridges that cycle on/off), use the average wattage listed on the energy label.
- Enter your daily usage in hours (or minutes — the calculator converts).
- Enter your electricity price per kWh. UK variable rate as of 2025: check your latest bill or the Ofgem price cap rate for your tariff type.
- Click Calculate. Results show cost per day, week, month, and year.
Typical Appliance Wattages and Annual Costs
| Appliance | Wattage | Typical use | Daily energy | Annual cost (UK 28p/kWh) |
|---|---|---|---|---|
| Electric shower (9 kW) | 9,000 W | 8 min/day | 1.2 kWh | ~£124 (at 28p/kWh) |
| Tumble dryer | 2,500 W | 1 hr, 5×/week | 1.79 kWh avg | ~£183 |
| Electric oven | 2,000–2,500 W | 1 hr/day | 2.0–2.5 kWh | ~£205–£256 |
| Washing machine | 500–2,000 W | 1 hr, 5×/week | 0.36–1.43 kWh avg | ~£37–£146 |
| Fridge-freezer | 100–400 W (running avg ~150W) | 24 hrs/day | 0.72–3.6 kWh | ~£74–£369 |
| 65-inch 4K TV | 100–200 W | 4 hrs/day | 0.4–0.8 kWh | ~£41–£82 |
| LED bulb (equivalent to 60W) | 8–10 W | 5 hrs/day | 0.04–0.05 kWh | ~£4–£5 |
| Desktop PC + monitor | 200–400 W | 4 hrs/day | 0.8–1.6 kWh | ~£82–£164 |
| Laptop | 20–80 W | 4 hrs/day | 0.08–0.32 kWh | ~£8–£33 |
| Electric vehicle charging (7 kW home charger) | 7,000 W | Varies — typical 6–8 kWh/charge | Variable | ~£483–£644 (at 28p; 10,000 miles/year at 3.5 miles/kWh) |
Finding Your Electricity Unit Price
Your electricity unit price (cost per kWh) appears on your electricity bill — look for "unit rate" or "pence per kWh." UK electricity prices have varied significantly in recent years:
- 2019: Average ~14p/kWh
- 2022 peak: Up to 34p/kWh (October 2022 price cap)
- 2024–2025: Typically 22–28p/kWh under Ofgem price cap
Additionally, most UK electricity bills include a standing charge (a fixed daily cost) and some tariffs (Economy 7, smart tariffs like Octopus Go) offer different rates for peak and off-peak hours.
Understanding Wattage vs. kWh
Wattage (W) is a measure of power — the rate at which an appliance uses energy. kWh is a measure of energy — the total amount of energy consumed over time. The relationship is: Energy (kWh) = Power (kW) × Time (hours).
- A 100W bulb running for 10 hours uses: 0.1 kW × 10 h = 1 kWh
- A 2,000W kettle running for 3 minutes uses: 2 kW × (3/60) h = 0.1 kWh
- A 10W LED bulb running for 100 hours uses: 0.01 kW × 100 h = 1 kWh (the same as the 100W bulb for 10 hours — same energy, much less power)
Your electricity meter counts kWh consumed. Your electricity company charges per kWh. The calculator converts wattage to kWh using your entered usage time.
Reading Appliance Energy Labels
EU and UK energy labels (the coloured A-G scale) indicate relative energy efficiency:
- A-rated: Most efficient (very few products achieve this — the scale was reset in 2021)
- D-rated: Around average for many appliance categories
- G-rated: Least efficient
The label also shows annual energy consumption in kWh under standard test conditions. This figure allows direct comparison between models. However, actual usage will differ from the test figure depending on your specific usage patterns.
Energy Saving Tips
| Tip | Estimated annual saving | How it works |
|---|---|---|
| Switch to LED bulbs | £100–£200/year for a whole house | LED uses 8W vs 60W incandescent; same light output. Payback period: 2–6 months. |
| Reduce shower time | £50–£150/year | Electric shower: every minute saved at 9 kW = 0.15 kWh. 2 minutes less/day = ~55 kWh/year = ~£15. |
| Use appliances at off-peak times | £50–£200/year on Economy 7 or smart tariffs | Economy 7 and Octopus Go offer cheaper electricity at night; run dishwasher, washing machine, EV charger overnight. |
| Don't leave devices on standby | £30–£80/year | UK average standby waste: ~£30/year. Smart plugs with timers or physical switches eliminate standby consumption. |
| Upgrade to an energy-efficient fridge-freezer | £50–£150/year over 15 years | A+ vs A+++ rating: significant difference. Old fridges (10+ years) typically use 3–4× more energy than modern equivalents. |
| Wash clothes at 30°C instead of 40°C | ~40% of wash cycle energy | Most modern detergents work effectively at 30°C. Lower temperature washes use significantly less energy. |
Smart Meters and Real-Time Monitoring
A smart meter communicates your electricity and gas usage to your supplier automatically, eliminating estimated bills. The in-home display (IHD) shows real-time energy consumption in kWh and estimated cost — letting you see immediately when a high-power appliance switches on.
Some smart monitors (clip-on CT sensor monitors like those from Loop or Hildebrand) connect to your home Wi-Fi and provide detailed usage breakdowns on a smartphone app. These can identify which appliances account for the most electricity, allowing targeted energy-saving action.
Common Questions
How do I find the wattage of an appliance?
The wattage is printed on a label on the appliance (often on the bottom, back, or inside the door), in the product manual, or on the manufacturer's website. Look for "W" (watts) or "kW" (kilowatts). For appliances with variable power (air conditioners, dishwashers), use the rated power or average power figure. Smart plugs with energy monitoring (like TP-Link Kasa or Shelly) can measure actual real-time wattage for any plugged-in appliance.
Does keeping appliances on standby really cost much?
Most individual standby consumptions are small (1–5W per device), but they run 24 hours a day, every day. A TV on 3W standby for 20 hours/day (4 hours watched, 20 hours standby): 3W × 20h = 60 Wh = 0.06 kWh/day = ~£6/year. Across all the standby devices in a home (TV, set-top box, broadband router, microwave, etc.), £30–£80/year total is a realistic estimate for an average UK home.
What uses the most electricity in a typical home?
Space heating (if electric), hot water heating (immersion heater or heat pump), and electric showers are usually the biggest energy consumers. After these, washing machines, tumble dryers, ovens, and always-on appliances like fridge-freezers are typically the next largest contributors. Lighting has become much less significant since the LED transition reduced typical household lighting consumption by 80–90%.
Calculate Your Electricity Costs
Enter any appliance's wattage, daily usage, and your electricity price to find out exactly what it costs to run.
Open Electricity Bill Calculator