Economy 7 — the honest maths

Calculate your night usage percentage right now

Check your supplier app for day vs night usage split. Calculate: night units divided by total units equals your night percentage.

• Under 30% overnight — Economy 7 is costing you more. Switch to a standard tariff.
• 30–40% overnight — roughly break-even. Compare standard deals anyway.
• Over 40% overnight — Economy 7 is working for you.

Who E7 genuinely works for

• Storage heater homes — designed to charge overnight
• EV owners charging overnight with no gas heating
• Homes with large hot water cylinders timed to heat overnight