UK Energy Tariff Switching Calculator (2026)

Compare the Ofgem Price Cap to fixed-rate energy tariffs for your DNO region, property type and usage. Shows annual savings, break-even cap-reduction threshold, seasonal monthly costs, and exit-fee risk.

⏱️ 3-5 minutes • 💪 Quick

Updated April 2026

How This Tool Works

📋 Purpose

When should you fix your energy tariff? When should you ride the Ofgem cap? This tool models both for your region, property and usage — showing annual savings, break-even cap-reduction threshold, and a seasonal monthly breakdown so you can plan cashflow.

⚙️ How It Works

  1. 1
    Enter region, property type, bedrooms and payment method.
  2. 2
    Enter actual kWh from last statement (or leave 0 to estimate).
  3. 3
    Select contract appetite (12m, 24m or either).
  4. 4
    Click Calculate for cap vs fix comparison.
  5. 5
    Review break-even threshold before switching.

UK Energy Tariff Switching — Fixed vs Ofgem Price Cap

Compare fixed-rate tariffs to the Ofgem Price Cap

The cap changes every 3 months. When forward wholesale prices are falling, staying on the cap often makes sense. When they rise — fixing locks in a lower rate. This tool shows the break-even: how far the cap must drop before fixing stops saving.

Your property & usage

If you leave usage at 0, the tool will estimate based on property profile.

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Complete Guide: UK Energy Tariff Switching (2026)

Ofgem cap mechanics, when to fix, payment method discounts and exit-fee traps.

📅 Last updated: April 2026

Quick Tips

Jump-start your understanding with these essential tips

Monthly DD is the baseline cap price. Paying on demand adds a premium.

Rule of thumb: fix if you think cap rises >5% next period and fix is at or below current cap.

Default estimates are off by ±30%. Your annual statement has exact usage.

Ofgem rule: you can switch free in the final 7 weeks of your contract.

Octopus, Good Energy offer genuine renewables at cap-level — no premium needed.

Step-by-Step Guide

Follow these steps to get the most from this tool

Region sets DNO-specific standing and unit rates. Property type + bedrooms estimate usage.

Direct Debit is default benchmark. Standard credit/prepayment apply small premium.

Your last annual statement shows exact elec and gas kWh. Use these for precision.

12-month, 24-month, or either. Longer fixes typically save more but lock you in.

See cap cost, best fix, annual savings, break-even threshold, and seasonal monthly breakdown.

Rates change weekly. Confirm with the supplier or MSE Cheap Energy Club before committing.

Advanced Topics

Deep dives for advanced users

The cap lags wholesale prices by 3–5 months. If wholesale is falling (summer 2024 → autumn 2024), cap will fall 3 months later. Conversely, a winter gas-price spike means the April cap will rise. Cornwall Insight publishes cap forecasts monthly — use these to judge fix timing. The Q2 2026 baseline in this tool is illustrative — confirm the current cap at ofgem.gov.uk.

Octopus Agile (half-hourly wholesale-pegged) and Octopus Go (5p/kWh off-peak 12:30–4:30am) can beat the cap dramatically for EV owners and users with heat pumps or battery storage. Requires a smart meter and some load-shifting. Not modelled in this tool — check Octopus directly.

Older electric-heating properties use Economy 7 with night-time rate (~12p/kWh) and day rate (~28p/kWh). If you have storage heaters or an immersion heater, E7 can be 20–30% cheaper. Requires an E7 meter. Standard smart meters can be reconfigured for E7 mode.

Some suppliers (British Gas Essentials, EDF Energy Assistance) offer lower rates for vulnerable customers on Pension Credit, Universal Credit, or with certain medical conditions. Always worth asking your supplier. Citizens Advice (0808 223 1133) helps with disputes, debt and eligibility. The Energy Bills Discount Scheme ended April 2024 but Warm Home Discount remains at £150.

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