Calories to British Thermal Units (cal → BTU)
Formula
1 cal = 0.00396565124258336 BTUConversion Table
| cal | BTU |
|---|---|
| 0 | 0 |
| 1.0000 | 0.0039657 |
| 2.0000 | 0.0079313 |
| 3.0000 | 0.011897 |
| 4.0000 | 0.015863 |
| 5.0000 | 0.019828 |
| 6.0000 | 0.023794 |
| 7.0000 | 0.027760 |
| 8.0000 | 0.031725 |
| 9.0000 | 0.035691 |
| 10.000 | 0.039657 |
| 11.000 | 0.043622 |
| 12.000 | 0.047588 |
| 13.000 | 0.051553 |
| 14.000 | 0.055519 |
| 15.000 | 0.059485 |
| 16.000 | 0.063450 |
| 17.000 | 0.067416 |
| 18.000 | 0.071382 |
| 19.000 | 0.075347 |
| cal | BTU |
|---|---|
| 20.000 | 0.079313 |
| 21.000 | 0.083279 |
| 22.000 | 0.087244 |
| 23.000 | 0.091210 |
| 24.000 | 0.095176 |
| 25.000 | 0.099141 |
| 26.000 | 0.10311 |
| 27.000 | 0.10707 |
| 28.000 | 0.11104 |
| 29.000 | 0.11500 |
| 30.000 | 0.11897 |
| 31.000 | 0.12294 |
| 32.000 | 0.12690 |
| 33.000 | 0.13087 |
| 34.000 | 0.13483 |
| 35.000 | 0.13880 |
| 36.000 | 0.14276 |
| 37.000 | 0.14673 |
| 38.000 | 0.15069 |
| 39.000 | 0.15466 |
| cal | BTU |
|---|---|
| 40.000 | 0.15863 |
| 41.000 | 0.16259 |
| 42.000 | 0.16656 |
| 43.000 | 0.17052 |
| 44.000 | 0.17449 |
| 45.000 | 0.17845 |
| 46.000 | 0.18242 |
| 47.000 | 0.18639 |
| 48.000 | 0.19035 |
| 49.000 | 0.19432 |
| 50.000 | 0.19828 |
| 51.000 | 0.20225 |
| 52.000 | 0.20621 |
| 53.000 | 0.21018 |
| 54.000 | 0.21415 |
| 55.000 | 0.21811 |
| 56.000 | 0.22208 |
| 57.000 | 0.22604 |
| 58.000 | 0.23001 |
| 59.000 | 0.23397 |
| cal | BTU |
|---|---|
| 60.000 | 0.23794 |
| 61.000 | 0.24190 |
| 62.000 | 0.24587 |
| 63.000 | 0.24984 |
| 64.000 | 0.25380 |
| 65.000 | 0.25777 |
| 66.000 | 0.26173 |
| 67.000 | 0.26570 |
| 68.000 | 0.26966 |
| 69.000 | 0.27363 |
| 70.000 | 0.27760 |
| 71.000 | 0.28156 |
| 72.000 | 0.28553 |
| 73.000 | 0.28949 |
| 74.000 | 0.29346 |
| 75.000 | 0.29742 |
| 76.000 | 0.30139 |
| 77.000 | 0.30536 |
| 78.000 | 0.30932 |
| 79.000 | 0.31329 |
Calories to British Thermal Units Conversion
Converting Calories (cal) to British Thermal Units (BTU) is a common energy and power conversion. 1 cal equals 0.003966 BTU. For example, 100 cal is equal to 0.396565 BTU.
Quick Mental Math: Calories to British Thermal Units
5 calories is 0.01983 british thermal units, so use that as the mental anchor.
Why is converting Calories to British Thermal Units tricky?
calories to british thermal units mixes thermal units with rate units, so people often miss whether the value is energy or energy per hour.
Quick Reference Values
1 cal = 0.003966 BTU. 5 cal = 0.019828 BTU. 10 cal = 0.039657 BTU. 25 cal = 0.099141 BTU. 50 cal = 0.198283 BTU. 100 cal = 0.396565 BTU.
What is Calories?
Calories (cal) is a unit of energy and power. The calorie (cal) is defined as exactly 4.184 joules. It quantifies the energy needed to raise the temperature of one gram of water by 1°C under standard conditions. The calorie is widely used in chemistry and nutrition to express energy content [bipm-si-brochure]. The calorie was introduced in the early 19th century by Nicolas Clément and standardized internationally in the 20th century. It was adopted for practical energy measurement in chemistry and food science before the joule became the SI unit [bipm-si-brochure]. Calories remain common in food labeling, nutrition, and chemistry worldwide. The dietary Calorie (kcal) is prevalent in the US, Europe, and many countries while scientific contexts prefer the joule [bipm-si-brochure].
What is British Thermal Units?
British Thermal Units (BTU) is a unit of energy and power. The British Thermal Unit (BTU) measures energy and is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. One BTU equals approximately 1055.06 joules in the International System of Units (SI). This unit is standardized for heating and cooling system capacities and energy content calculations [nist-sp-811]. The BTU originated in the mid-19th century during the industrial revolution to quantify heat energy for steam engines and heating systems. It was standardized by engineering societies to unify thermal energy measurements in the United Kingdom and the United States [nist-sp-811]. BTU remains widely used in the United States, the United Kingdom, and Canada for HVAC system ratings and energy content in fuels. It is recognized by industry standards and energy regulations but is less common in countries using the SI system exclusively [nist-sp-811].
Common Misspellings
People often search for this conversion using these alternate spellings: calorie, cal, calory, calo, british thermal unit, btu unit, british therm unit, btu energy, british thermals unit. All of these refer to the Calories to British Thermal Units conversion.