Convert Calories to Watt-hours
Convert Calories to Watt-hours instantly. 1 Calory (cal) equals 0.001162 Watt-hours (Wh).
Calories to Watt-hours conversion table
| Calories (cal) | Watt-hours (Wh) |
|---|---|
| 1 cal | 0.001162 Wh |
| 2 cal | 0.002324 Wh |
| 3 cal | 0.003487 Wh |
| 5 cal | 0.005811 Wh |
| 10 cal | 0.01162 Wh |
| 20 cal | 0.02324 Wh |
| 50 cal | 0.05811 Wh |
| 100 cal | 0.1162 Wh |
| 500 cal | 0.5811 Wh |
| 1,000 cal | 1.1622 Wh |
1 Calory = 0.001162 Watt-hours · multiply Calories by 0.001162
About converting Calories to Watt-hours
Calories (cal) and Watt-hours (Wh) are both units of energy, so converting between them is a single multiplication: multiply your Calories figure by 0.001162. Ten Calories comes to 0.01162 Watt-hours, and a hundred works out at 0.1162 Watt-hours.
Rule of thumb: going from Calories to Watt-hours divides, so the figure always shrinks — it takes about 860.4207 Calories to make a single Watt-hour. If your answer came out bigger, you have the conversion the wrong way round.
What is a Calory?
The calorie is the unit most likely to be misread, because there are two of them. The small calorie — the one this converter uses — is approximately the heat needed to warm a gram of water by one degree Celsius, and it is a tiny amount of energy. The "calories" printed on food labels are not these: a food Calorie, traditionally written with a capital C, is a thousand small calories, properly a kilocalorie. So a 2,000-calorie daily diet is really about 8.4 million small calories. Several slightly different calories were defined historically; the thermochemical calorie used here is fixed at exactly 4.184 joules.
What is a Watt-hour?
A watt-hour is energy, not power, and that distinction trips people up constantly. A watt is a rate — energy per second — so a watt-hour is what you get by sustaining that rate for an hour: a quantity of energy expressed as "this much power for this long". It is the natural unit for anything that stores energy and releases it gradually, which is why phone and laptop batteries are rated in watt-hours rather than the milliamp-hours stamped on the cell, and why airlines police lithium batteries by their watt-hour rating. Capacity in watt-hours tells you how long a load can run; watts alone never can.
To put both in perspective: an apple holds roughly 95,000 small calories, while a phone battery holds somewhere around 15 watt-hours.
The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Watt-hours to Calories converter, or browse all Energy converters.
Frequently asked questions
How many Watt-hours are in one Calory?
There are 0.001162 Watt-hours in one Calory.
How do I convert Calories to Watt-hours?
Multiply the number of Calories by 0.001162. For example, 10 Calories = 0.01162 Watt-hours.
What is 100 Calories in Watt-hours?
100 Calories is equal to 0.1162 Watt-hours.
How do I convert Watt-hours to Calories?
Multiply the Watt-hours value by 860.4207 (or divide by 0.001162).
Is this Calories to Watt-hours conversion exact?
The definition is exact — Calories and Watt-hours are both fixed against the same base by international agreement — but the decimal shown here is rounded for readability, because the true ratio does not terminate. For engineering or scientific work, carry more decimal places than this page displays.
What is a Calory?
The calorie is the unit most likely to be misread, because there are two of them. The small calorie — the one this converter uses — is approximately the heat needed to warm a gram of water by one degree Celsius, and it is a tiny amount of energy. The "calories" printed on food labels are not these: a food Calorie, traditionally written with a capital C, is a thousand small calories, properly a kilocalorie. So a 2,000-calorie daily diet is really about 8.4 million small calories. Several slightly different calories were defined historically; the thermochemical calorie used here is fixed at exactly 4.184 joules.
What is a Watt-hour?
A watt-hour is energy, not power, and that distinction trips people up constantly. A watt is a rate — energy per second — so a watt-hour is what you get by sustaining that rate for an hour: a quantity of energy expressed as "this much power for this long". It is the natural unit for anything that stores energy and releases it gradually, which is why phone and laptop batteries are rated in watt-hours rather than the milliamp-hours stamped on the cell, and why airlines police lithium batteries by their watt-hour rating. Capacity in watt-hours tells you how long a load can run; watts alone never can.