Calories to Therms (cal to thm) Converter

How to convert calories to therms

Formulathm = cal × 3.966613703×10⁻⁸

Multiply the value in calories by 3.966613703×10⁻⁸. To go the other way, multiply by 25,210,420.65 (or divide by 3.966613703×10⁻⁸).

A calorie is smaller than a therm: it takes 25,210,420.65 calories to make one therm.

Worked examples

1 calorie (thermochemical)1 cal × 3.966613703×10⁻⁸ = 3.966613703×10⁻⁸ thm
5 calories5 cal × 3.966613703×10⁻⁸ = 1.983306851×10⁻⁷ thm
10 calories10 cal × 3.966613703×10⁻⁸ = 3.966613703×10⁻⁷ thm
20 calories20 cal × 3.966613703×10⁻⁸ = 7.933227405×10⁻⁷ thm
100 calories100 cal × 3.966613703×10⁻⁸ = 0.000003966613703 thm

Calories to therms conversion table

Values are calculated by the conversion engine and rounded to 8 significant figures.

Calories to therms: 0.1–10 cal
Calories (cal)	Therms (thm)
0.1 cal	3.9666137×10⁻⁹ thm
0.25 cal	9.9165343×10⁻⁹ thm
0.5 cal	1.9833069×10⁻⁸ thm
1 cal	3.9666137×10⁻⁸ thm
2 cal	7.9332274×10⁻⁸ thm
3 cal	1.1899841×10⁻⁷ thm
4 cal	1.5866455×10⁻⁷ thm
5 cal	1.9833069×10⁻⁷ thm
6 cal	2.3799682×10⁻⁷ thm
7 cal	2.7766296×10⁻⁷ thm
8 cal	3.173291×10⁻⁷ thm
9 cal	3.5699523×10⁻⁷ thm
10 cal	3.9666137×10⁻⁷ thm

Calories to therms: 12–1,000 cal
Calories (cal)	Therms (thm)
12 cal	4.7599364×10⁻⁷ thm
15 cal	5.9499206×10⁻⁷ thm
20 cal	7.9332274×10⁻⁷ thm
25 cal	9.9165343×10⁻⁷ thm
30 cal	0.0000011899841 thm
40 cal	0.0000015866455 thm
50 cal	0.0000019833069 thm
75 cal	0.0000029749603 thm
100 cal	0.0000039666137 thm
250 cal	0.0000099165343 thm
500 cal	0.000019833069 thm
1,000 cal	0.000039666137 thm

About the units

Calorie (cal)

The “small” calorie: exactly 4.184 J (thermochemical definition), roughly the energy to heat one gram of water by 1 °C.

Therm (thm)

The US therm is 105,480,400 J, about 100,000 BTU. US gas utilities bill by the therm.

Frequently asked questions

How many therms are in one calorie?

There are 3.966613703×10⁻⁸ therms in one calorie, and this value is exact by definition.

How do I convert calories to therms?

Multiply the number of calories by 3.966613703×10⁻⁸. For example, 10 cal × 3.966613703×10⁻⁸ = 3.966613703×10⁻⁷ thm.

How many calories are in one therm?

One therm equals 25,210,420.65 calories. That is the reverse factor, 1 ÷ 3.966613703×10⁻⁸.

What is 10 calories in therms?

10 cal = 3.966613703×10⁻⁷ thm.

Is this cal to thm converter accurate?

Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.

Calories to Therms Converter