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Energy Cost Calculator FAQ

Everything you need to know about UK energy costs and saving money

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🧮 Using the Calculator

How is energy cost calculated?

Energy cost is calculated using the formula:

Daily cost = (Wattage ÷ 1000) × Hours used per day × Unit cost (£/kWh)

For example, a 2000W kettle used for 1 hour per day at £0.28/kWh costs: (2000 ÷ 1000) × 1 × 0.28 = £0.56 per day, or £16.80 per month.

How do I find the wattage of my appliances?

Check the appliance's rating plate (usually on the back or bottom) for wattage (W) or power consumption. If only amperage (A) is listed, calculate watts using:

Watts = Amps × 230V (UK voltage)

For example, a device rated at 5A uses 5 × 230 = 1150W. You can also use a plug-in energy monitor for accurate real-time measurements.

What is a kilowatt-hour (kWh)?

A kilowatt-hour (kWh) is a unit of energy equal to using 1000 watts for one hour. It's how energy companies measure and bill your electricity usage. For example, a 100W light bulb running for 10 hours uses 1 kWh. At £0.28 per kWh, that 1 kWh costs 28 pence.

💷 UK Energy Prices

What is the average UK electricity price in 2026?

As of 2026, the average UK electricity price is approximately £0.24-£0.34 per kWh, depending on your region, supplier, and tariff type. Check your latest energy bill for your specific unit rate. Prices vary significantly between standard and Economy 7 tariffs.

Is it cheaper to use electricity at night?

It depends on your tariff. Economy 7 and Economy 10 tariffs offer cheaper electricity during off-peak hours (typically 11pm-7am for Economy 7). However, daytime rates are often higher to compensate. These tariffs benefit households that can shift heavy usage to night-time, such as running dishwashers, washing machines, or charging electric vehicles overnight.

🔌 Appliance Energy Usage

What appliances use the most electricity?

The highest electricity consumers in UK homes are typically:

  • Electric showers (7000-10500W)
  • Electric heating systems (2000-3000W)
  • Tumble dryers (2000-3000W)
  • Electric ovens (2000-2500W)
  • Kettles (2000-3000W)
  • Washing machines (1200-2500W)
  • Dishwashers (1200-2400W)

However, devices left on 24/7 like fridges and freezers also contribute significantly to annual costs.

How much does it cost to run a fridge-freezer?

A typical modern energy-efficient fridge-freezer (A++ rated, 200-300W) costs approximately £40-£60 per year to run. Older models (500W+) can cost £100-£150 annually. Since fridge-freezers run 24/7, upgrading to an energy-efficient model can save £50-£90 per year.

What is phantom power or standby consumption?

Phantom power is electricity consumed by devices when they're turned off but still plugged in. Common culprits include TVs, game consoles, phone chargers, microwaves with digital clocks, and computers. In the average UK home, standby power accounts for 9-16% of total electricity use, costing £45-£80 per year. Use power strips to easily switch off multiple devices.

💡 Energy Saving Tips

How can I reduce my electricity bill?

Key ways to reduce electricity bills include:

  • Switch to LED bulbs (75% less energy than incandescent)
  • Unplug devices on standby mode
  • Use energy-efficient appliances (A++ rated or better)
  • Wash clothes at 30°C instead of 40°C
  • Air-dry laundry instead of tumble drying
  • Use a microwave instead of an oven when possible
  • Keep your fridge at 3-5°C and freezer at -18°C
  • Boil only the water you need in the kettle
  • Use lids on pots when cooking
  • Defrost your freezer regularly

Should I turn off appliances at the wall?

Yes, for most appliances. Devices on standby consume 0.5-15W each, which adds up over time. Priority appliances to switch off include TVs, game consoles, phone chargers, microwaves, and desktop computers. However, some devices like smart TVs, broadband routers, and security systems may need to stay on for updates or functionality.

How can I make my heating more energy-efficient?

For electric heating:

  • Use a programmable thermostat
  • Lower room temperature by 1°C (saves ~10%)
  • Insulate your home properly
  • Use draft excluders on doors and windows
  • Close curtains at dusk to retain heat
  • Bleed radiators regularly
  • Heat only the rooms you use most

Are smart meters worth it for saving energy?

Smart meters themselves don't save energy, but they provide real-time information about your energy usage, helping you identify high-consumption patterns and make informed decisions. Studies show households with smart meters typically reduce consumption by 2-10% through better awareness of their usage habits.

⚡ Quick Win Energy Savings

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LED Bulbs

Save £35/year by switching to LEDs

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Switch Off Standby

Save £45-£80/year

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Lower Thermostat 1°C

Save 10% on heating costs

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Wash at 30°C

Use 40% less electricity

Boil What You Need

Save £11/year on kettle costs

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Air Dry Clothes

Save £60/year vs tumble dryer

📊 Typical UK Appliance Running Costs

Based on average usage patterns and £0.28/kWh electricity rate:

Appliance Typical Wattage Annual Cost
Fridge-Freezer (A++ rated) 200-300W £40-£60
Washing Machine (3x/week) 2000W £25-£35
Tumble Dryer (3x/week) 2500W £85-£120
Dishwasher (5x/week) 1500W £40-£55
Electric Oven (4hrs/week) 2400W £55-£70
Kettle (5x/day, 3 mins) 3000W £35-£45
TV (4hrs/day) 100-150W £15-£25
Desktop Computer (8hrs/day) 200W £45-£55
LED Light Bulb (5hrs/day) 10W £1.50-£2
Electric Shower (30 mins/day) 9000W £150-£200