Calculate a UK electricity bill from your kWh usage, unit rate, standing charge and billing period — with VAT included.
Electricity bill · kWh · standing charge · VAT
Use the kWh shown for this billing period, not always a calendar month.
Find this on your electricity bill or online account.
Use 30 for a monthly bill or the exact days on your statement.
Bill = (kWh used × unit rate) + (standing charge × days) + VAT. At 250 kWh, 24.5p/kWh, 60p/day standing charge over 30 days with 5% VAT, the total is about £83 for the period.
The standing charge applies every day regardless of usage, which is why low-consumption homes still see meaningful bills.
The unit rate charges you for each kWh consumed. The standing charge is a flat daily fee for being connected to the grid. Both appear on your bill and both matter when comparing tariffs.
A tariff with a very low unit rate but a high standing charge can suit heavy users. A low standing charge with a higher unit rate can work better if you use little electricity.
Your kWh usage is usually shown as "electricity used" or "consumption" for the billing period. The unit rate is labelled "unit rate" or "pence per kWh". The standing charge is shown as a daily rate in pence.
Paper bills, PDF statements and online account dashboards all show these figures. Enter the exact billing period in days if it is not a calendar month — many suppliers use 28–33 day cycles.
Multiply your kWh usage by your unit rate in pence, divide by 100 to get pounds, then add the standing charge (pence per day × number of days, divided by 100). Add VAT on the subtotal — usually 5% for domestic supply. The calculator above does this automatically and projects an annual estimate from your billing period.
The standing charge is a fixed daily fee covering grid connection and supplier costs. You pay it every day whether you use electricity or not. On a typical UK tariff it might be 50–70p per day, which adds £180–£250 a year before any units are used. Low-use households feel standing charges more because they make up a larger share of the total bill.
Yes. Domestic electricity bills include VAT at 5% on the combined energy and standing charge costs. Some business supplies are charged at 20% VAT. The calculator defaults to 5% — adjust if your bill shows a different rate.
The average UK household uses around 2,700 kWh of electricity a year, which works out to roughly 225 kWh per month. Flats and low-use homes may be closer to 150 kWh; larger homes with electric heating, EV charging or heat pumps can exceed 400 kWh in winter months.
Standing charges and fixed daily costs still apply even at low usage. If you use 100 kWh a month but pay 60p/day standing charge, the fixed portion can be a large share of the bill. Comparing tariffs on both unit rate and standing charge matters for low-use homes.
This calculator works from your total kWh usage and bill rates — ideal when you know your consumption and tariff from a statement. The appliance electricity cost calculator works from individual appliance wattage and hours of use. Use this page for whole-bill estimates; use the appliance calculator to see what one device contributes.
