The US therm
The US therm equals exactly 100,000 BTU (IT), or 105,480,400 joules. It is the standard billing unit for residential natural-gas consumption in the United States.
US therms to BTU Converter
1 thm = 99976.1 BTU (US therm → BTU)
1 thm = 99976.1 BTU
1 US therm equals 99976.1 BTU. To convert US therms to BTU, multiply the US therm value by 99976.1. For quick reference: 1 thm = 99976.1 BTU, 5 thm = 499881 BTU, 10 thm = 999761 BTU, 100 thm = 9997613 BTU.
Formula
BTU = US therms × 99976.1Quick
How to convert US therms to BTU
Take your value
Start with your value in US therms.
Multiply by 99976.1
Multiply the US therm value by 99976.1. This is the exact conversion factor from US therms to BTU.
Read the result
The product is your value in BTU. For example, 5 thm × 99976.1 = 499881 BTU.
Conversion formula
The exact factor from US therms to BTU is 99976.1.
BTU = US therms × 99976.1
US therms to BTU conversion table
Fifty common reference values, hand-picked for skim utility. Use the calculator above for any value not listed.
| US therms (thm) | BTU (BTU) |
|---|---|
| 0.001 thm | 99.976 BTU |
| 0.01 thm | 999.76 BTU |
| 0.1 thm | 9997.6 BTU |
| 0.5 thm | 49988 BTU |
| 1 thm | 99976 BTU |
| 1.5 thm | 149964 BTU |
| 2 thm | 199952 BTU |
| 5 thm | 499881 BTU |
| 10 thm | 999761 BTU |
| 20 thm | 1999523 BTU |
| 50 thm | 4998806 BTU |
| 100 thm | 9997613 BTU |
| 200 thm | 19995226 BTU |
| 250 thm | 24994032 BTU |
| 500 thm | 49988064 BTU |
| 1000 thm | 99976129 BTU |
| 2000 thm | 199952258 BTU |
| 2500 thm | 249940322 BTU |
| 3600 thm | 359914064 BTU |
| 5000 thm | 499880645 BTU |
| 7500 thm | 749820967 BTU |
| 10000 thm | 999761290 BTU |
| 25000 thm | 2499403224 BTU |
| 50000 thm | 4998806449 BTU |
| 100000 thm | 9997612898 BTU |
| 250000 thm | 24994032244 BTU |
| 500000 thm | 49988064489 BTU |
| 1000000 thm | 99976128977 BTU |
| 2000000 thm | 199952257955 BTU |
| 3600000 thm | 359914064319 BTU |
| 5000000 thm | 499880644887 BTU |
| 10000000 thm | 999761289775 BTU |
| 25000000 thm | 2499403224437 BTU |
| 50000000 thm | 4998806448875 BTU |
| 100000000 thm | 9997612897750 BTU |
| 250000000 thm | 24994032244374 BTU |
| 500000000 thm | 49988064488748 BTU |
| 1000000000 thm | 99976128977497 BTU |
| 2000000000 thm | 199952257954994 BTU |
| 5000000000 thm | 499880644887484 BTU |
| 10000000000 thm | 999761289774968 BTU |
| 20000000000 thm | 1.9995 × 10^15 BTU |
| 50000000000 thm | 4.9988 × 10^15 BTU |
| 100000000000 thm | 9.9976 × 10^15 BTU |
| 1000000000000 thm | 9.9976 × 10^16 BTU |
| 10000000000000 thm | 9.9976 × 10^17 BTU |
| 100000000000000 thm | 9.9976 × 10^18 BTU |
| 1000000000000000 thm | 9.9976 × 10^19 BTU |
| 10000000000000000 thm | 9.9976 × 10^20 BTU |
| 100000000000000000 thm | 9.9976 × 10^21 BTU |
Real-world reference
A US household uses roughly 3–10 therms of natural gas per month in summer. A typical gas furnace might consume 1 therm per hour of runtime. In BTU, that gives you: 1 thm = 99976.1 BTU, 10 thm = 999761 BTU, 100 thm = 9997613 BTU.
Frequently asked questions
- How many BTU are in 1 US therm?
- 1 US therm equals 99976.1 BTU.
- How do I convert US therms to BTU?
- Multiply the US therm value by 99976.1. So x thm × 99976.1 = the equivalent in BTU.
- What is 5 US therms in BTU?
- 5 US therms equals 499881 BTU.
- What is 10 US therms in BTU?
- 10 US therms equals 999761 BTU.
- What is 100 US therms in BTU?
- 100 US therms equals 9997613 BTU.
- How do I convert back from BTU to US therms?
- Multiply the BTU value by 1.0002 × 10^−5. For example, 1 BTU = 1.0002 × 10^−5 thm.
- Is the US therm bigger than the BTU?
- Yes. 1 US therm is larger than 1 BTU — specifically 99976.1 times larger.
- Are these conversion factors exact?
- The underlying imperial/US unit definitions are exact; the displayed factor (99976.1) is rounded for readability, and the browser computes using IEEE 754 double-precision arithmetic.
About the US therm and the BTU
The BTU
The International Table BTU (British thermal unit) equals exactly 1,055.05585262 joules — the energy needed to raise 1 pound of water by 1 °F. It is the dominant unit in US HVAC and natural-gas billing. There is also a thermochemical BTU that differs by about 0.06% — we use the more common IT definition.