HeatPumpSwitch › Tools
All ten calculators
Every calculator runs in your browser. Nothing you type is sent anywhere, and every one shows its working and its assumptions.
Running-cost calculator
Your fuel in, delivered heat out, then the heat pump cost for the same heat — every step shown.
Grant eligibility checker
All programmes in all four countries in one table, with check dates.
German February 2027 loss calculator
What delaying a German application past the cut costs, in euros.
Break-even price-ratio calculator
The price ratio that decides whether a heat pump can win at all.
SCOP reality simulator
Catalogue 4.2 against field 2.5, in money and in years.
Heat pump sizing from heat loss
A defensible kW number to check a quote against.
Radiators vs underfloor heating
What your existing radiators can hold, and whether you need to touch them.
Hybrid (keep the boiler) calculator
Keeping the boiler for the coldest days: when the arithmetic favours it.
BUS budget tracker
How much of the £400m is left, from Ofgem's monthly figure.
Installer question checklist
Twenty questions to print and take to every quote.
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Get quotes for your property
Compare at least three installers. Ask each one for the heat-loss calculation and the design flow temperature in writing — that number decides your running cost more than the brand on the box.
Ad. If you request a quote through this link we may be paid a commission by the installer. It does not change your price, and we do not rank companies by how much they pay.