Convert therms to BTU

1 thm=100,000BTU

Use the converter below to change any therms value into BTU instantly — with formula, conversion table, and real-world examples.

You have

Equals

100,000

Conversion formula

Forward

BTU = therms × 100,000

Reverse

therms = BTU × 1.0000e-5

Example: 10 thm × 100,000 = 1,000,000 BTU.

About both units

From

Therm

thm

The therm equals 100,000 BTU or 105.5 megajoules. Used in US and UK natural-gas billing. A typical UK home uses 200–500 therms per year for heating.

Real-world: UK home heating: 200–500 therms/year. 1 therm = about $1.50 US (2024) or £1.00 UK.

Read full therm reference →

British Thermal Unit

BTU

The British Thermal Unit equals approximately 1055 joules — the energy to raise 1 pound of water by 1 °F. Used for HVAC, heating, and air-conditioning capacity in the US. A 9000 BTU/h AC is a small room unit.

Real-world: Window AC: 5000–12,000 BTU/h. Central AC: 24,000–60,000 BTU/h. Home furnace: 60,000–100,000 BTU/h.

Read full british thermal unit reference →

Therm to British Thermal Unit conversion table

Common therms to BTU values for quick reference.

Therm (thm)	British Thermal Unit (BTU)
1 thm	100,000 BTU
10 thm	1,000,000 BTU
100 thm	10,000,000.03 BTU
500 thm	50,000,000.14 BTU
1,000 thm	100,000,000.28 BTU
5,000 thm	500,000,001.42 BTU
10,000 thm	1,000,000,002.84 BTU
50,000 thm	5,000,000,014.22 BTU
100,000 thm	10,000,000,028.43 BTU
500,000 thm	50,000,000,142.17 BTU

Tips & common mistakes

Quick tips

1 therm = 100,000 BTU = 105.5 MJ = 29.3 kWh.
UK bills often quote both therms and kWh.
In metric-dominant EU, gas is billed in kWh or m³.

Avoid these

Comparing therms and kWh without conversion on a mixed-unit bill.
Assuming therms are used globally — only US and UK.
Using BTU when bill shows therms — factor of 100,000.

Frequently asked questions

How many BTU in a therm?

One therm equals 100,000 BTU.

How do I convert therms to BTU?

Multiply the therm value by 100,000 to get the equivalent in BTU.

What is 100 therms in BTU?

100 therms equals 10,000,000.03 BTU.

Is a therm bigger than a british thermal unit?

Yes. 1 therm equals 100,000 BTU, so one therm is larger.

How to convert therms to BTU without a calculator?

Multiply by 100,000 for a quick estimate; use a calculator for precise results.

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