Energy decision hub
Energy Savings Calculators for Homes and Businesses
Stop guessing your energy costs.
Compare heating, cooling and efficiency upgrades with local prices, units and clear payback estimates.
Annual savings
ExampleAnnual savings
35% cost reduction
Current annual cost
Payback period
0.0years
Optimised system
£0
Browse calculators
Illustrative only — your results use local rates and building data.
What do you want to decide today?
Pick a goal and jump straight into the right calculator.
Featured calculators
Start with the tools that drive the biggest energy decisions.
Home energy calculators
Heating, cooling, efficiency and consumption tools for homeowners
Showing 6 of 16 home tools
Business calculators
Professional tools for contractors, facility managers and commercial properties
HVAC System Calculator
Design and cost complete commercial HVAC systems
Coming soon for commercial HVAC planning
Building Energy Audit
Run a structured commercial energy audit
Coming soon for energy auditors
Industrial Heating Calculator
Model heating costs for industrial facilities
Coming soon for warehouses and plants
Multi-Zone Calculator
Calculate heating across multiple zones
Coming soon for multi-zone buildings
ROI Analysis Tool
Analyse return on heating system upgrades
Coming soon for investment planning
Why Thermopy
Built to turn energy data into decisions you can act on.
Accurate
Engineering-based estimates instead of rule-of-thumb guesses
Local
Results in your currency, language, and metric or imperial units
Actionable
Clear costs, savings and payback you can take to an installer
Built for local markets worldwide
13 currencies plus metric and imperial units — so results match how you buy energy.
Metric
m² · °C · kW
Imperial
ft² · °F · BTU / tons
17 live calculators
Heating, cooling, efficiency and business
From Guesswork to Clear Energy Decisions
Volatile heating and electricity prices make accurate cost planning essential for homes and businesses. Thermopy is an energy decision hub: free HVAC and energy calculators that turn building data into local costs, savings and payback — so you can size AC, compare heat pumps, radiators and insulation before you spend.
18 Live Calculators for Heating, Cooling and Efficiency
Our suite of 18 energy savings calculators translates engineering inputs into actionable financial figures in your currency. From AC sizing and cooling comparison to heat pump ROI, radiator sizing, insulation payback and commercial LED audits, Thermopy replaces rough estimates with decision-ready numbers. Every calculator is built to handle:
- ✓13 Global Currencies (USD, EUR, GBP, PLN, NOK, SEK, CZK, SAR, and others).
- ✓Metric and Imperial Units (m²↔ft², °C↔°F, kW↔BTU).
Whether you manage a warehouse in Berlin or a home in Texas, results stay locally precise and ready to share with an installer. Local accuracy is the difference between a guess and a plan.
Your Path to Lower Energy Bills
Use our professional-grade tools to immediately:
- 1.Calculate payback for major heating, cooling and efficiency investments.
- 2.Pinpoint where energy money is leaking in your home or business.
- 3.Compare true running costs of heating and cooling systems in your region.
Start with one click. Choose a calculator below to turn energy from a complex problem into a clear savings opportunity — with numbers you can act on.
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