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Calculators

Seven calculators. One straight answer each.

Pick the question you have. Each tool models your home from a few inputs and shows the assumptions behind the result, so you can sense-check it before you ever speak to an installer. Every output is an estimate, not a quote.

How they work

Why you can trust the number

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Real data, not rules of thumb

Solar yield comes from PVGIS satellite irradiance for your exact location. Tariffs track the Ofgem price cap. Heat-pump efficiency uses a SCOP you can change.

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The maths is shown

Each result lists the figures that shaped it. Nothing is hidden behind a "request a quote" wall, and the inputs are yours to adjust.

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No tuning to upsell

The estimate is not nudged toward a bigger system. We would rather be useful than optimistic. Quotes are optional and never required to see your result.

These are estimates, not quotes
Real performance and prices vary with your roof, installer and equipment. Use the numbers to decide whether something is worth pricing up, then get a written quote from an MCS-certified installer. See our disclaimers.