Economy 7 or an EV tariff? Comparing your night rate with 7.6p

If you already have Economy 7 and get an electric car, you have two ways to charge cheaply at night: keep Economy 7 and charge in its off-peak hours, or move to an EV tariff. The answer depends on your own rates, which is why this page doesn’t publish a single Economy 7 rate. Read yours from your bill and put them into the calculator below.

What Economy 7 is

• Citizens Advice describes Economy 7 as usually 7 hours of off-peak electricity per 24 hours, normally in one block overnight, for example 11pm to 6am. Economy 10 gives 10 hours, which can be split into blocks through the day.
• The exact hours depend on your meter and supplier. They are on your bill or in your online account.
• Ofgem’s price cap allows a multi-rate tariff to have different peak and off-peak rates, as long as together they stay within the cap.

Compare your two options

Enter rates in pence per kWh. The car’s kWh is miles ÷ miles per kWh (find yours in all 142 cars). Home kWh is from your bill or smart meter data. Standing charges are left out; add them from your quotes if they differ.

7.6p is pre-filled as Intelligent Octopus Go’s night rate. Its window (23:30–05:30) is shorter than a typical Economy 7 block, so if a lot of your home night use falls outside it, put that in the day box for the EV tariff. Other EV tariffs’ rates are in UK EV tariffs compared.

When an EV tariff usually wins

• Its night rate is lower than your Economy 7 night rate, and its day rate isn’t much higher than your Economy 7 day rate. The car’s kWh are often the biggest single load, so the night rate does most of the work.
• Smart EV tariffs can also give the car (and, on Intelligent Octopus Go, the home) the low rate at extra times, which Economy 7 doesn’t.

When Economy 7 may still be right

• Storage heaters. They are designed to charge on an Economy 7 or Economy 10 block (Citizens Advice). British Gas says its EV tariff doesn’t work with Economy 7 storage heaters, and that it is better to stay on Economy 7 in that case. Ask any supplier the same question before switching.
• A longer cheap window matters to you, for example a cylinder and storage heaters that need the full seven hours.
• No smart meter. EV tariffs need a smart meter that sends half-hourly readings. Economy 7 can run on an older two-rate meter.

On Economy 7 a 7.4 kW charger can add up to 51.8 kWh in a seven-hour block, so the window itself is rarely the limit for the car. If you’re checking whether Economy 7 still pays at all, see is Economy 7 worth it?.

Questions people ask

Is Economy 7 or an EV tariff cheaper for charging an electric car?

It depends on your rates. Compare (car kWh + home night kWh) × each night rate + home day kWh × each day rate. Economy 7 rates vary by supplier and region, so use the ones on your bill.

Can I charge an EV on Economy 7?

Yes. Set the car or charger to charge inside your Economy 7 hours, which are on your bill. Citizens Advice says Economy 7 is usually 7 hours overnight, for example 11pm to 6am.

Should I switch from Economy 7 if I have storage heaters?

Check with the supplier first. Storage heaters are designed around an Economy 7 or 10 block, and British Gas says its EV tariff doesn’t work with Economy 7 storage heaters.

Is this financial advice?

No. The calculator only does the arithmetic on the rates you enter.

Sources

• Citizens Advice, choosing an energy tariff (Economy 7 and Economy 10)
• Citizens Advice, using storage heaters and immersion heaters
• British Gas, EV tariff FAQ (Economy 7 and storage heaters)
• Octopus Energy, EV tariff eligibility (half-hourly smart meter)
• Octopus Energy, Intelligent Octopus Go (checked 15 October 2026)
• Ofgem, energy price cap unit rates and standing charges (1 October–31 December 2026)
• PlugLater, UK EV tariffs compared (checked 15 October 2026)

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