Energy bills are measured in a unit nobody visualises. Fix that, and everything else — the price cap, the standing charge debate, which appliances actually cost money — snaps into focus.
What Is a kWh?
One kilowatt-hour runs a 1kW appliance for one hour. In real life: one dishwasher cycle, ~7 hours of TV, 90 phone charges, or 20 minutes of electric shower. At ~24.5p/kWh for electricity and ~6.3p for gas, the same heat from gas costs a quarter of the electric price — the whole heat-pump economics debate in one sentence.
The Four Parts of Your Bill
- Unit rates × usage — the only part you control day to day
- Standing charges — ~60p/day combined, payable even in an empty house
- VAT at 5% on the lot
- Within the unit rate: wholesale energy (~40%), network costs, policy levies and supplier margin
Your Gas Meter Does Not Measure kWh
It measures volume. The bill converts: m³ × 1.02264 × calorific value (~39.5) ÷ 3.6 = kWh. Imperial meters (older, dial-type) measure hundreds of cubic feet — multiply by 2.83 first. Running your own readings through the formula is the definitive way to check an estimated bill.
The Big Levers
Heating dominates (~60% of a typical dual-fuel bill), so thermostat discipline (1°C ≈ ~10% of heating cost), heating the person not the house, and shorter showers beat obsessing over phantom standby loads worth £30/year.