How to Convert Therms to Kilowatt-hours (thm to kWh)

Updated 5 Oct 2026 in Unit Converters

Energy conversions link food labels in kJ and kcal, SP Group bills in kWh and air-conditioner capacity in BTU. This guide shows how to convert therms into kilowatt-hours by hand, with examples and a quick-reference table.

The conversion

To convert therms to kilowatt-hours, multiply the value by 29.3071070158. To go the other way, divide by the same number (or multiply by 0.0341214163). For a quick estimate, multiply by about 29.

Kilowatt-hours = therms × 29.3071070158

Worked examples

• 3 thm = 87.9213 kWh
• 12.5 thm = 366.3388 kWh
• 75 thm = 2,198.03 kWh

Therms to Kilowatt-hours table

Common questions

Is thm to kWh exact?

The factors used here are the internationally defined values where they exist; results are rounded for display only.

How do I convert back?

Use the Kilowatt-hours to Therms converter.

Mistakes to avoid

Dropping the units

A bare number without a unit is easy to misread later. Always write the unit with the result.

Forgetting squared and cubed units

Area and volume factors are the length factor squared or cubed, so 1 m² is about 10.76 sq ft, not 3.28.

Rounding the factor too early

Using 3 instead of 3.28 for feet per metre introduces an error of almost 9% before you have started.

Background

A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.

Many conversion factors are exact by definition. The inch has been defined as exactly 2.54 centimetres since 1959, and the pound as exactly 0.45359237 kilograms, so conversions involving them can be as precise as you need.

Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.

For any value, use the Therms to Kilowatt-hours Converter or browse all energy converters.

Run your own numbers: Therms to Kilowatt-hours Converter