Energy Savings Calculator UK

Our free UK energy savings calculator estimates how much you could save annually by switching from your current energy tariff to a cheaper deal. It works by comparing the unit rates and standing charges between your existing tariff and a new one, then applying those rates to your actual (or typical) annual consumption figures.

Here is what the calculator takes into account: Unit rate difference — the cost per kilowatt-hour (kWh) you pay for electricity and gas. Even a saving of 1p–2p/kWh can add up to over £100/year for a typical household. Standing charge comparison — the daily fixed charge you pay regardless of how much energy you use. This varies significantly between suppliers. Annual consumption — your actual kWh usage for gas and electricity, or Ofgem's typical domestic consumption values (TDCV) if you don't know yours. Direct debit saving — based on your current monthly payment, we calculate what your new monthly direct debit would be under the cheaper tariff. Smart meter saving — if you have a smart meter, your supplier can provide exact 12-month usage figures, making the calculator significantly more accurate.

Your current electricity and gas unit rates are shown on your energy bill (paper or digital), in your online account or energy app, or on the original contract email you received when you signed up. Look for 'electricity unit rate,' 'gas unit rate,' and 'standing charge.' If you cannot find them, we have pre-filled the current Ofgem price cap defaults so you can still get an indicative saving.

What is a good annual saving? The size of your saving depends on several factors — your usage, your current tariff, and what deals are available at the time. In 2024–2025, competitive fixed-rate tariffs are available at 5–15% below the price cap, which equates to roughly £100–£300/year for a typical household. Households with higher-than-average usage (e.g., electric vehicles, working from home, older boilers) tend to save more in absolute terms.

The unit rate is the price you pay for each kilowatt-hour (kWh) of energy you consume. The standing charge is a fixed daily cost just for being connected to the grid — regardless of how much you use.

Smart meter benefit: If you have a smart meter, your supplier can provide exact 12-month usage figures via your online account or app. Using real data instead of estimates makes this calculator significantly more accurate.