Energy & Utilities

Energy Bill Calculator UK — Estimate Your Gas & Electric Costs

Calculate your energy bills based on usage. Average costs, unit rates, standing charges, and tips to estimate your annual gas and electricity spend.

· 4 min read

Understanding how your energy bill is calculated helps you budget and find savings. Here’s how to estimate your costs.

Energy Price Cap Rates

Current Cap (April 2025)

Component Electricity Gas
Unit rate ~24.5p/kWh ~6.24p/kWh
Standing charge ~60p/day ~32p/day

*Rates shown are typical; actual rates vary by region and payment method.

Typical Annual Bills (Price Cap)

Household Size Annual Bill
Small (1-2 bed flat) £1,200-1,400
Medium (3-bed semi) £1,600-1,900
Large (4-5 bed) £2,200-2,800

How Bills Are Calculated

The Formula

Total Bill = Standing Charges + Usage Charges

Standing Charges = Daily rate × Number of days
Usage Charges = Unit rate × kWh consumed

Example Calculation (Monthly)

Component Calculation Cost
Electricity
Standing charge £0.60 × 30 days £18.00
Usage 242 kWh × £0.245 £59.29
Electricity total £77.29
Gas
Standing charge £0.32 × 30 days £9.60
Usage 833 kWh × £0.0624 £51.98
Gas total £61.58
Monthly total £138.87
Annual total ~£1,666

Average Usage by Property

Electricity Usage (Annual kWh)

Property Type Low Medium High
1-bed flat 1,500 2,000 2,500
2-bed flat 1,800 2,400 3,000
2-bed house 2,100 2,700 3,400
3-bed house 2,400 2,900 3,900
4-bed house 2,800 3,800 5,100
5+ bed house 3,400 4,600 6,100

Gas Usage (Annual kWh)

Property Type Low Medium High
1-bed flat 6,000 8,000 10,000
2-bed flat 7,000 10,000 13,000
2-bed house 8,000 11,000 15,000
3-bed house 9,000 12,000 17,000
4-bed house 11,000 15,000 21,000
5+ bed house 14,000 19,000 26,000

Estimate Your Annual Bill

Step-by-Step Calculator

Step Your Input
1. Annual electricity (kWh) _______
2. × unit rate (£0.245) = £_______
3. + standing charge (365 × £0.60) + £219
Electricity total = £_______
4. Annual gas (kWh) _______
5. × unit rate (£0.0624) = £_______
6. + standing charge (365 × £0.32) + £117
Gas total = £_______
Annual total = £_______

Quick Estimate Table

Annual Usage Electric (kWh) Gas (kWh) Annual Bill
Low 1,800 7,500 £1,150
Medium-low 2,400 10,000 £1,400
Medium 2,900 12,000 £1,650
Medium-high 3,500 15,000 £2,000
High 4,300 18,000 £2,400
Very high 5,500 23,000 £3,050

Appliance Running Costs

Common Appliances

Appliance Power (Watts) Hours/Day kWh/Day Weekly Cost
LED TV 50W 4 0.2 £0.34
Laptop 50W 8 0.4 £0.69
Desktop PC 200W 8 1.6 £2.74
Games console 150W 3 0.45 £0.77
Fridge-freezer 40W 24 0.96 £1.65
Washing machine 500W 1 (6×/wk) N/A £0.74
Tumble dryer 3000W 1 (3×/wk) N/A £2.21
Dishwasher 1800W 1 1.8 £3.09
Kettle 3000W 0.25 0.75 £1.29
Electric oven 2000W 1 2.0 £3.43
Microwave 1000W 0.3 0.3 £0.51
Electric shower 9000W 0.17 1.5 £2.57
Hair dryer 2000W 0.17 0.34 £0.58

Heating Costs (Electric)

Heater Type Power Cost Per Hour
Oil-filled radiator 1.5kW £0.37
Fan heater 2kW £0.49
Halogen heater 1.2kW £0.29
Panel heater 1kW £0.25
Storage heater (charging) 2kW £0.49
Electric blanket 0.1kW £0.02

Seasonal Variation

Typical Monthly Usage Pattern

Month Electric (kWh) Gas (kWh) Combined Cost
January 280 1,800 £185
February 260 1,600 £170
March 240 1,300 £150
April 220 900 £115
May 210 500 £90
June 200 300 £75
July 200 300 £75
August 200 300 £75
September 220 500 £90
October 240 1,000 £130
November 260 1,400 £160
December 280 1,800 £185
Annual 2,810 11,700 ~£1,500

Compare Tariffs

Tariff Types

Tariff Type Features
Standard variable Default, price cap protected
Fixed rate Locked price for 1-2 years
Green/renewable From renewable sources
Economy 7/10 Cheaper night rates
Prepayment Pay as you go

When to Fix

Situation Recommendation
Prices expected to rise Fix now
Prices expected to fall Stay on variable
Want certainty Fix
Low usage May not matter much

Ways to Reduce Bills

Quick Wins

Action Typical Saving
Switch supplier/tariff £100-300/year
Turn down thermostat 1°C £80-100/year
Switch off standby £55/year
LED bulbs £40/year
Efficient shower head £70/year (water & energy)
Draught proofing £30-50/year

Bigger Investments

Action Cost Annual Saving Payback
Loft insulation £300-500 £200+ 2-3 years
Cavity wall insulation £500-1,500 £150-300 3-5 years
Smart thermostat £150-250 £75-150 2-3 years
Solar panels £5,000-8,000 £300-500 10-15 years
Heat pump £10,000-15,000 £200-500 20-30+ years

Behavioural Changes

Change Impact
Shorter showers Significant
Full washing machine loads Moderate
Air dry clothes £50+/year
Cook efficiently Moderate
Layer up instead of heating Significant

Standing Charges

Why We Pay Them

Purpose Details
Network maintenance Pipes, wires, infrastructure
Meter costs Reading, maintenance
Policy costs Some green levies
Fixed regardless of usage Can’t avoid

Current Standing Charges

Fuel Daily Charge Annual Total
Electricity ~60p ~£219
Gas ~32p ~£117
Total ~92p ~£336

Impact on Low Users

Situation Impact
Holiday home High proportion in standing charges
Very efficient home Still pay full standing charge
Electric-only (no gas) Save £117/year gas standing charge

Summary

Household Typical Annual Bill
1-2 bed flat £1,200-1,400
3-bed house £1,600-1,900
Large house £2,200-2,800
Cost Component Typical Rate
Electricity unit 24-25p/kWh
Gas unit 6-7p/kWh
Electricity standing 60p/day
Gas standing 32p/day