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Ofgem Price Cap Impact Calculator UK

See what the new Ofgem default-tariff price cap means for your annual and monthly energy bill. Updated every quarter — compare the current cap against the one it replaced for your electricity and gas use.

#tariffs

Interactive Ofgem price cap impact calculator

Worked example

A typical UK dual-fuel direct-debit household using 2,700 kWh of electricity and 11,500 kWh of gas per year:

New cap period
1 April – 30 June 2026
Previous cap period
1 January – 31 March 2026
Bill under new cap
£1762/yr
Bill under prior cap
£1761/yr
Annual change
£1
Monthly change
£0.05

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What the Ofgem price cap actually caps

  • Unit rate (p/kWh) for electricity and gas on the default (non-fixed) tariff.
  • Daily standing charge (p/day) — what you pay whether you use any energy or not.
  • It does not cap your total bill — use more, pay more.
  • It does not apply to fixed tariffs you've signed up to.
  • Rates vary by payment method (direct debit cheapest, standard credit most expensive).
  • There are 14 regional variants by DNO letter — this calculator uses the UK single-rate default.

Frequently asked questions

What is the Ofgem price cap?
The default-tariff price cap is Ofgem's quarterly-reset ceiling on the unit rate and standing charge that most GB energy suppliers can charge customers on default (non-fixed) tariffs. It covers roughly 29 million UK households. It does not cap your bill — if you use more, you pay more; it caps the per-kWh rate and per-day standing charge. Fixed-tariff deals sit outside the cap.
How often does the cap change?
Four times a year: 1 January, 1 April, 1 July and 1 October. Ofgem announces the new cap roughly six weeks before it takes effect.
Does the cap vary by region?
Yes, slightly. There are 14 regional caps (by DNO letter) that vary by a few percent from the UK single-rate default shown here. This calculator uses the UK single-rate figures — regional detail is on the v2 roadmap.
What's the difference between direct debit, prepayment and standard credit?
Direct debit is the cheapest — you pay monthly by DD, the supplier is guaranteed payment, and standing charges are at the lowest rate. Prepayment meters have slightly different rates (in some quarters cheaper, in others dearer). Standard credit (you pay on receipt of each bill) is the most expensive — higher unit rates and standing charges to cover supplier cash-flow and bad-debt risk.
How accurate are these numbers?
Unit rates and standing charges are the officially-published Ofgem cap figures. Your actual bill may vary by a small amount due to regional cap variation, partial-quarter crossover (the cap changes mid-cycle), metering quirks, and VAT rounding. The calculator gives you a defensible headline number — not a penny-exact forecast.

How this calculator works

The calculator multiplies your annual electricity and gas use by the unit rate for your payment method under each of the two most recent Ofgem cap periods, adds the daily standing charge × 365, and reports the difference. That gives you a defensible like-for-like comparison — one cap period vs the one it replaced — rather than an abstract "bills go up" headline.

The quarterly rhythm matters. Ofgem announces the next cap about six weeks before it takes effect, and the figures make national news every time. But the headline number is always based on Ofgem's "typical dual-fuel direct-debit household" (2,700 kWh electricity, 11,500 kWh gas). If you use more than that — a poorly-insulated detached home, a large family, a heat pump running on electricity — your £ impact is proportionally larger. If you're electric-only or on a tiny flat, it's smaller. This calculator gives you the number for your home, not the headline household.

What v1 doesn't model

  • Regional caps. UK single-rate only. Regional variation is ±3% for most homes.
  • Economy-7 / multi-rate meters. Night and day rates aren't split.
  • Partial-quarter crossover. If you want to compare last year's total bill to this year's, you'd need to blend four caps; we diff the latest two cleanly.
  • Long-range history. We only keep current + prior. Older history is stripped on update — see the expansion notes for keeping a full timeline.

When this isn't the right answer

If you're on a fixed tariff, the cap doesn't apply to you until your fix ends — your rates are whatever you signed up to. If you're in Northern Ireland, the cap doesn't apply at all; NI has a different regulated market. And if you're trying to decide whether to fix now or ride the cap, this calculator tells you what the cap costs — you'll also want to compare against live fixed deals from your supplier or a comparison site. If you're willing to shift consumption across the day, Octopus Agile is a third option that often beats both the cap and a fix.

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