Free General calculator

General MEP unit converter

Convert common building-services units for power, energy, airflow, water flow, pressure, temperature, length, area, volume, velocity and illuminance.

Enter the project values

All values remain in your browser. Review the assumptions before using the result.

Your result will appear here.Calculate to see the outputs, formula and substituted working.

How the calculation works

Fixed mathematical unit relationships, with offsets applied for absolute temperature.

Formula

Converted value = input × source factor ÷ target factor

Worked example

Input1 kW

Output3,412.142 Btu/h

Temperature example32°F = 0°C

Assumptions and limitations

Assumptions

Conversions use fixed factors.
UK gallon means imperial gallon.

What this does not check

Does not convert between mass and volume without density.
Standard-condition corrections for gases are not included.

Formula version: 1.0 · Last reviewed: 16 August 2026

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Engineering basis: first-principles calculation using user-entered project data. The calculator does not choose design criteria or replace the complete project-specific engineering design.

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