Convert energy units — joules, kilowatt-hours, calories, BTU, electron volts and more.
| Unit | Name | Value |
|---|---|---|
| 0.001 therm | 25210.4 cal | |
| 0.01 therm | 252104 cal | |
| 0.1 therm | 2.52104e+06 cal | |
| 1 therm | 2.52104e+07 cal | |
| 5 therm | 1.26052e+08 cal | |
| 10 therm | 2.52104e+08 cal | |
| 50 therm | 1.26052e+09 cal | |
| 100 therm | 2.52104e+09 cal | |
| 1000 therm | 2.52104e+10 cal |
Formula: Calorie = Therm × 2.521e+07
Multiply any therm value by 2.521e+07 to get calorie.
Reverse: Therm = Calorie × 3.9666e-8
Common therm values — factor: 1 therm = 2.521e+07 cal
| Therm (therm) | Calorie (cal) | Context |
|---|---|---|
| 0.001 therm | 2.521e+04 cal | 0.1 kWh |
| 0.01 therm | 2.521e+05 cal | 1 kWh |
| 0.1 therm | 2.521e+06 cal | 3 kWh |
| 1 therm | 2.521e+07 cal | 29.3 kWh |
| 10 therm | 2.521e+08 cal | Monthly gas fraction |
| 50 therm | 1.261e+09 cal | Half winter month |
| 100 therm | 2.521e+09 cal | Monthly winter gas |
| 500 therm | 1.261e+10 cal | Seasonal heating |
| 1,000 therm | 2.521e+10 cal | Annual home gas |
| 1e+04 therm | 2.521e+11 cal | Commercial building |
| 1e+05 therm | 2.521e+12 cal | Large industrial |
| 1e+06 therm | 2.521e+13 cal | Utility scale |
| 1.000e+09 therm | 2.521e+16 cal | Regional supply |
| 1.000e+12 therm | 2.521e+19 cal | National supply |
| 1.000e+15 therm | 2.521e+22 cal | Global scale |
1 therm = 2.521e+07 cal. Memorize for instant estimates.
Use 2.521e+07 as a quick mental multiplier.
Multiply result by 3.9666e-8 to recover the original therm value.
Bills residential and commercial customers in therms per billing cycle.
Calculates annual gas consumption for boilers and furnaces in therms.
Trades natural gas contracts denominated in therms or MMBTU.
Monitors and benchmarks gas use in therms per square foot per year.
Sizes gas pipes and appliances based on BTU/hour and therm ratings.
Models household and industrial gas demand in therms per year.
The therm is a unit of natural gas energy equal to 100,000 BTU (105,480,400 joules). It is the standard billing unit for natural gas in the United States and United Kingdom. The name comes from the Greek thermos (heat).
Gas utilities bill residential and commercial customers in therms in the US and UK. A typical US household uses about 50–100 therms per month in winter. Natural gas furnaces and water heaters are rated in therms per hour.
Interesting fact: One therm of natural gas costs about $1.00–$2.00 in the US. Burning one therm releases about 5.3 kg of CO₂. The US consumes about 28 trillion therms of natural gas equivalent energy per year.
The calorie (cal) was defined in 1824 as the heat needed to raise 1 gram of water by 1°C. There are two versions: the small calorie (cal = 4.184 J) and the large calorie or kilocalorie (kcal = 4,184 J), which is the 'Calorie' used in nutrition.
The calorie remains standard in chemistry for heat of reaction measurements. In the US, food packaging uses 'Calories' (with capital C) which are actually kilocalories — a persistent source of confusion.
Interesting fact: The confusion between cal and kcal means that a food label saying '200 Calories' actually means 200 kcal = 200,000 cal = 836,800 joules. The SI unit for food energy is the kilojoule.
Converting therm to calorie is common across energy, nutrition, engineering, and science. Different sectors use different energy units — joules in physics, kcal in nutrition, kWh in electricity, and BTU in HVAC — making accurate conversion essential for cross-disciplinary work and international comparisons.
Quick reference: 5 therm = 1.261e+08 cal and 10 therm = 2.521e+08 cal. Reverse: 1 cal = 3.9666e-8 therm. Exact factor: 1 therm = 2.521e+07 cal.
All conversions use IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.