How to Convert Therms to Watt-hours (thm to Wh)
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 watt-hours by hand, with examples and a quick-reference table.
The conversion
To convert therms to watt-hours, multiply the value by 29,307.1070158333. To go the other way, divide by the same number (or multiply by 3.412142e-05). For a quick estimate, multiply by about 29,000.
Watt-hours = therms × 29,307.1070158333
Worked examples
- 3 thm = 87,921.32 Wh
- 12.5 thm = 366,338.84 Wh
- 75 thm = 2,198,033.03 Wh
Therms to Watt-hours table
| Therms | Watt-hours |
|---|---|
| 1 thm | 29,307.11 Wh |
| 2 thm | 58,614.21 Wh |
| 5 thm | 146,535.54 Wh |
| 10 thm | 293,071.07 Wh |
| 20 thm | 586,142.14 Wh |
| 25 thm | 732,677.68 Wh |
| 50 thm | 1,465,355.35 Wh |
| 100 thm | 2,930,710.7 Wh |
| 250 thm | 7,326,776.75 Wh |
| 500 thm | 14,653,553.51 Wh |
| 1,000 thm | 29,307,107.02 Wh |
Common questions
Is thm to Wh 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 Watt-hours to Therms converter.
Mistakes to avoid
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
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.
Background
Singapore adopted the metric system in the 1970s, replacing imperial units and traditional Chinese measures in most official uses. Metric units are now standard in schools, trade and government, but older units survive in property, markets and imported goods.
A conversion table is handy for common values, but a calculator is faster and avoids interpolation errors for anything in between.
For everyday use, three or four significant figures are usually enough. Engineering, science and trade documents may need more, and rounding should happen only at the end of a calculation.
For any value, use the Therms to Watt-hours Converter or browse all energy converters.
Run your own numbers: Therms to Watt-hours Converter