25 cal to Wh — 25 calories in watt-hours
Exact 25 ÷ 860.42065 = 0.02905556
25 calories in other units
| Joules | 104.6 | J |
|---|---|---|
| Kilojoules | 0.1046 | kJ |
| Megajoules | 0.0001046 | MJ |
| Watt-hours | 0.02905556 | Wh |
| Kilowatt-hours | 0.000029055556 | kWh |
| Kilocalories | 0.025 | kcal |
| British thermal units | 0.09914167 | BTU |
| Therms | 9.9142e-7 | thm |
| Foot-pounds | 77.149001 | ft·lbf |
| Electronvolts | 652,861,849,188,595,924,992 | eV |
cal to Wh at a glance
| Calories | Watt-hours |
|---|---|
| 1 cal | 0.001162222222 Wh |
| 2 cal | 0.002324444444 Wh |
| 3 cal | 0.003486666667 Wh |
| 5 cal | 0.005811111111 Wh |
| 10 cal | 0.01162222 Wh |
| 20 cal | 0.02324444 Wh |
| 25 cal | 0.02905556 Wh |
| 50 cal | 0.05811111 Wh |
| 100 cal | 0.11622222 Wh |
| 250 cal | 0.29055556 Wh |
| 500 cal | 0.58111111 Wh |
| 1,000 cal | 1.162222 Wh |
How to convert calories to watt-hours
Multiply by 0.001162222222 — one calorie is 0.001162222222 watt-hours. 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 25 ÷ 860.42065 = 0.02905556
What these units are
The calorie and the watt-hour are covered in the energy unit guide, along with every other unit on this page.
Questions
How many watt-hours are in a calorie?
One calorie is 0.001162222222 watt-hours. This figure is exact — it comes from the definition of the unit, not a measurement.
What is 25 calories in watt-hours?
25 calories is 0.02905556 watt-hours. The working is 25 ÷ 860.42065 = 0.02905556.
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.