Home / Everyday Money / Economy 7 / EV Tariff Checker
The short version
Check your actual meter registers. A smart meter may support time-of-use tariffs, but older RTS meters need attention.
The cheap rate only helps if you use it.
This checker compares a single-rate tariff with a two-rate Economy 7 or EV-style tariff using your night-use share and EV charging load.
Before switching, check meter compatibility and the exact off-peak hours. A low night rate with a punishing day rate can backfire.
Rules of thumb
When Economy 7 or EV tariffs help
Likely good fit Storage heaters, immersion heating, EV charging, battery charging or appliance timers shift a large share of use into off-peak hours.
Likely poor fit Most usage happens in the evening peak, and the day rate is much higher than a single-rate tariff.
Meter compatibility Ofgem says Economy 7 requires a meter that records peak and off-peak usage separately.
Sources Sources and useful links
About this calculator
Last reviewed: May 2026. Reviewed by the Editor against current HMRC guidance and the 2026/27 UK tax year.
Verified against: Ofgem - Economy 7 tariff guidance (checked on the last review date above).
Source: calculator JavaScript is unminified at /assets/ — see Open methodology for how to verify the math. Updates tracked in the changelog .
Disclaimer: This tool gives a guideline estimate using current published UK rates and thresholds. It is general information, not personal financial, tax, or legal advice. Verify the figures against your own circumstances, the latest gov.uk guidance, and a qualified adviser before acting. UK Tax Drag accepts no liability for decisions made on the basis of these calculations.
Every page is reviewed against the editorial standards, written from primary sources and sourced openly, with corrections listed in the changelog . No affiliate revenue. No sponsored content. No paid placements.
UK Tax Drag is an independent publication by Finsolve Consulting Limited, not affiliated with or endorsed by HMRC, GOV.UK or any government body.