Economy 7 calculator
Economy 7 only pays if enough of your electricity is used at night. Enter the rates from your bill and how much you use overnight to see whether it beats a single rate.
How this is calculated
On Economy 7, day units are charged at the day rate and night units at the night rate, plus the daily standing charge for 365 days.
The single-rate cost is all your units at the single rate plus its standing charge.
The break-even share is how much of your use has to fall in the night hours for the two to cost the same. Below it the single rate is cheaper, above it Economy 7 is.
Rates vary by supplier and region, so the day and night defaults are only examples. The comparison is only as good as the rates you enter.
Rates used · 2026/27
| Night hours | usually 7, set by your meter |
| Single rate example | 26.32p, the October 2026 cap average |
| Standing charge example | 54.83p a day, the October 2026 cap average |
| Billing year | 365 days |
Last checked July 2026. Source: HMRC and gov.uk.
Worked example
A home using 4,200 kWh a year with 40% at night pays £1,204 on Economy 7 at 30.5p by day and 14p at night, against £1,306 on a 26.32p single rate. That is £102 a year cheaper, and Economy 7 only wins once at least 26% of the use is at night.
Common questions
Is Economy 7 worth it?
Usually only if a large share of your electricity is used overnight, for storage heaters, hot water or charging a car. Most homes that use electricity mainly in the day pay more on Economy 7, because the day rate is higher than a single rate.
What are the Economy 7 night hours?
Seven hours, normally somewhere between 10pm and 8am. The exact times depend on your meter and region, and some meters do not change for British Summer Time.
How do I know how much I use at night?
An Economy 7 meter shows two readings, or your bill splits day and night units. Divide the night units by the total.
Can I switch off Economy 7?
Yes. Your supplier can change your meter settings or fit a single-rate meter. Smart meters can be switched remotely.