Convert Kilowatt-Hour to Therm (kWh → thm)

Converting kilowatt-hours to therms is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in kilowatt-hours

   Start with the number of kilowatt-hours (kWh) you want to convert.
2. 2
   Multiply by 0.034121

   The conversion factor from kWh to thm is 0.034121. Multiply your value by this number.
3. 3
   Read the result in therms

   The result is your value in therms (thm).

Multiply the value in kilowatt-hours by 0.034121. For the reverse direction, multiply by 29.307107.

• ✓1 kWh = 3.6 MJ = 3,600,000 J.
• ✓Multiply device power (kW) × time (h) = energy (kWh).
• ✓EV "range anxiety" translates to knowing kWh available.

• ✗Confusing kWh (energy) with kW (power).
• ✗Calculating electric costs by power ignoring duration.
• ✗Using "kWh/h" — redundant; it's just kW.

What is the Kilowatt-Hour?

The kilowatt-hour equals 1,000 watt-hours (3.6 megajoules) and is the universal billing unit for residential electricity consumption around the world. A typical US household uses about 800–1,000 kWh per month; a refrigerator consumes 1–2 kWh per day, an LED bulb at 10 W for 10 hours uses 0.1 kWh, and a Tesla Model 3 has a 75 kWh battery (about 250–350 miles of range). Electric utility rates are quoted in cents per kWh — typical US residential rates are 11–25 ¢/kWh, while industrial rates are lower. The kilowatt-hour is essential in renewable-energy planning: solar panel output, wind farm production, and grid-scale storage are all rated in kWh or MWh (megawatt-hours). It relates to the watt-hour (1,000 Wh = 1 kWh), the joule (1 kWh = 3.6 MJ), the BTU (1 kWh ≈ 3,412 BTU), and the megawatt-hour (1,000 kWh = 1 MWh).

• Electricity billing globally
• EV battery capacity specifications
• Home solar and battery storage

What is the Therm?

The therm equals exactly 100,000 BTU (or about 105.5 megajoules) and is the standard unit for natural-gas billing in the United States and the United Kingdom. Gas utilities deliver therms (or 'CCF' — hundred cubic feet, approximately 1 therm of natural gas). A typical US home uses 50–100 therms per month for heating in winter. The therm is also used in industrial process heating and commercial gas pricing. UK natural gas was historically sold in therms before metric conversion, and the unit persists in legacy contracts. The therm relates to the BTU (100,000 BTU = 1 therm), the megajoule (1 therm ≈ 105.5 MJ), the kilowatt-hour (1 therm ≈ 29.3 kWh), and the cubic foot of natural gas (about 100 ft³ ≈ 1 therm at standard heating value). Most metric countries bill natural gas in cubic meters or kilowatt-hours instead.

• US residential gas bills
• UK commercial gas billing
• Industrial natural-gas contracts