What is this calculator used for?

Heat Loss Calculator gives a quick formula-based estimate from the values you enter. Use it for sanity checks before quoting, ordering or planning.

Is this calculator free?

Yes. SectorCalc free calculators run in your browser with no sign-up required.

When should I use a premium analyzer?

Use a premium analyzer when the estimate affects pricing, operations or management decisions and you need hidden drivers, thresholds and export-ready reports.

Energy & carbon

Heat Loss Calculator

Steady-state heat loss in watts.

What is Heat Loss Calculator?

Calculate heat loss from U-value, area and temperature difference.

Enter values and calculate to see your result here.

Related calculators

How this calculator works

What this calculator does

Steady-state heat loss in watts.

Inputs used

U-value (W/m²K): Thermal transmittance Area (m²): Envelope area ΔT (°C): Inside minus outside

Formula summary

Energy and emissions estimates multiply consumption, tariff or emission factors from your inputs to show cost and carbon exposure.

What the result includes

Formula-based estimate from the inputs you enter
Primary result plus supporting secondary values where applicable
Plain-language explanation of what the numbers represent

What this estimate misses

This free result gives the first number. It does not include hidden drivers such as thresholds, benchmark comparison, sensitivity, export-ready report output or suggested action plans.

FAQ

What is this calculator used for?: Heat Loss Calculator gives a quick formula-based estimate from the values you enter. Use it for sanity checks before quoting, ordering or planning.
Is this calculator free?: Yes. SectorCalc free calculators run in your browser with no sign-up required.
When should I use a premium analyzer?: Use a premium analyzer when the estimate affects pricing, operations or management decisions and you need hidden drivers, thresholds and export-ready reports.

How this calculator works

What this calculator does

Steady-state heat loss in watts.

Inputs used

U-value (W/m²K): Thermal transmittance Area (m²): Envelope area ΔT (°C): Inside minus outside

Formula summary

Energy and emissions estimates multiply consumption, tariff or emission factors from your inputs to show cost and carbon exposure.

What the result includes

Formula-based estimate from the inputs you enter
Primary result plus supporting secondary values where applicable
Plain-language explanation of what the numbers represent

What this estimate misses

This free result gives the first number. It does not include hidden drivers such as thresholds, benchmark comparison, sensitivity, export-ready report output or suggested action plans.

FAQ

What is this calculator used for?: Heat Loss Calculator gives a quick formula-based estimate from the values you enter. Use it for sanity checks before quoting, ordering or planning.
Is this calculator free?: Yes. SectorCalc free calculators run in your browser with no sign-up required.
When should I use a premium analyzer?: Use a premium analyzer when the estimate affects pricing, operations or management decisions and you need hidden drivers, thresholds and export-ready reports.