1,000 cal to MJ — 1,000 calories in megajoules
Exact 1,000 ÷ 239,005.74 = 0.004184
1,000 calories in other units
| Joules | 4,184 | J |
|---|---|---|
| Kilojoules | 4.184 | kJ |
| Megajoules | 0.004184 | MJ |
| Watt-hours | 1.162222 | Wh |
| Kilowatt-hours | 0.001162222222 | kWh |
| Kilocalorie | 1 | kcal |
| British thermal units | 3.965667 | BTU |
| Therms | 0.000039656668 | thm |
| Foot-pounds | 3,085.96 | ft·lbf |
| Electronvolts | 26,114,473,967,543,832,805,376 | eV |
cal to MJ at a glance
| Calories | Megajoules |
|---|---|
| 1 cal | 0.000004184 MJ |
| 2 cal | 0.000008368 MJ |
| 3 cal | 0.000012552 MJ |
| 5 cal | 0.00002092 MJ |
| 10 cal | 0.00004184 MJ |
| 20 cal | 0.00008368 MJ |
| 25 cal | 0.0001046 MJ |
| 50 cal | 0.0002092 MJ |
| 100 cal | 0.0004184 MJ |
| 250 cal | 0.001046 MJ |
| 500 cal | 0.002092 MJ |
| 1,000 cal | 0.004184 MJ |
How to convert calories to megajoules
Multiply by 0.000004184 — one calorie is 0.000004184 megajoules. 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 1,000 ÷ 239,005.74 = 0.004184
What these units are
The calorie and the megajoule are covered in the energy unit guide, along with every other unit on this page.
Questions
How many megajoules are in a calorie?
One calorie is 0.000004184 megajoules. This figure is exact — it comes from the definition of the unit, not a measurement.
What is 1,000 calories in megajoules?
1,000 calories is 0.004184 megajoules. The working is 1,000 ÷ 239,005.74 = 0.004184.
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.