20 BTU to kcal — 20 British thermal units in kilocalories
Exact 20 ÷ 3.965667 = 5.043288
20 British thermal units in other units
| Joules | 21,101.12 | J |
|---|---|---|
| Kilojoules | 21.101117 | kJ |
| Megajoules | 0.02110112 | MJ |
| Watt-hours | 5.861421 | Wh |
| Kilowatt-hours | 0.005861421403 | kWh |
| Calories | 5,043.29 | cal |
| Kilocalories | 5.043288 | kcal |
| Therms | 0.0002 | thm |
| Foot-pounds | 15,563.39 | ft·lbf |
| Electronvolts | 131,702,813,563,813,351,129,088 | eV |
BTU to kcal at a glance
| British thermal units | Kilocalories |
|---|---|
| 1 BTU | 0.2521644 kcal |
| 2 BTU | 0.5043288 kcal |
| 3 BTU | 0.7564932 kcal |
| 5 BTU | 1.260822 kcal |
| 10 BTU | 2.521644 kcal |
| 20 BTU | 5.043288 kcal |
| 25 BTU | 6.30411 kcal |
| 50 BTU | 12.60822 kcal |
| 100 BTU | 25.21644 kcal |
| 250 BTU | 63.0411 kcal |
| 500 BTU | 126.0822 kcal |
| 1,000 BTU | 252.164401 kcal |
How to convert British thermal units to kilocalories
Multiply by 0.2521644 — one British thermal unit is 0.2521644 kilocalories. That factor is exact: it comes from the definition of the units rather than from a measurement, so it will not change and does not need rounding.
Working 20 ÷ 3.965667 = 5.043288
In words: about five kilocalories.
What these units are
The British thermal unit and the kilocalorie are covered in the energy unit guide, along with every other unit on this page.
Questions
How many kilocalories are in a British thermal unit?
One British thermal unit is 0.2521644 kilocalories. This figure is exact — it comes from the definition of the unit, not a measurement.
What is 20 British thermal units in kilocalories?
20 British thermal units is 5.043288 kilocalories. The working is 20 ÷ 3.965667 = 5.043288.
Is a food Calorie the same as a calorie?
No — it is a thousand of them. The Calorie on a nutrition label is a kilocalorie, written with a capital C in principle and almost never in practice. A 250 Calorie chocolate bar holds 250,000 physics calories, or about 1,046 kilojoules, which is why European labels quote kJ alongside.
What does a kilowatt-hour actually represent?
One kilowatt drawn for one hour — a 1,000 W heater running for sixty minutes, or a 100 W bulb for ten hours. It is the unit your electricity bill is priced in, and it equals exactly 3.6 million joules.
How much energy is one BTU?
Roughly the heat needed to raise one pound of water by one degree Fahrenheit — about 1,055 joules, or the energy in a single kitchen match. Air conditioners are rated in BTU per hour, where a 12,000 BTU/h unit is one "ton" of cooling and draws around 3.5 kW of heat.
Why is the electronvolt so small?
Because it is sized for single particles: it is the energy one electron picks up crossing a one-volt potential difference. At about 1.6 × 10⁻¹⁹ joules it would be absurd for anything larger, which is precisely why particle physics uses it instead of dragging around twenty leading zeros.