Watts to Calories Calculator
Convert watts (power) to calories per second, minute, or hour. One watt equals 0.239006 calories per second. This conversion is useful in thermodynamics, nutrition science, and understanding energy expenditure rates.
How to Convert Watts to Calories
- Take the power value in watts.
- Multiply by 0.239006 to get calories per second.
- For calories per minute, multiply the result by 60.
- For calories per hour, multiply by 3600.
Formula
cal/s = Watts x 0.239006
cal/min = Watts x 0.239006 x 60 = Watts x 14.3404
cal/hr = Watts x 0.239006 x 3600 = Watts x 860.421
Example Calculation
A 75W light bulb running for 1 hour:
Calories per hour = 75 x 860.421 = 64,532 cal = 64.5 kcal
This means the bulb releases about 64.5 food Calories of heat energy per hour.
Watts to Calories Reference Table
| Watts | cal/s | cal/min | cal/hr |
|---|---|---|---|
| 10 | 2.39 | 143.40 | 8604.22 |
| 50 | 11.95 | 717.02 | 43021.08 |
| 100 | 23.90 | 1434.04 | 86042.16 |
| 200 | 47.80 | 2868.07 | 172084.32 |
| 500 | 119.50 | 7170.18 | 430210.80 |
| 1000 | 239.01 | 14340.36 | 860421.60 |
Frequently Asked Questions
What is the difference between calories and kilocalories?
1 kilocalorie (kcal) = 1000 calories (cal). Food "Calories" (capital C) are actually kilocalories. So 100 food Calories = 100 kcal = 100,000 cal.
How many watts does the human body produce?
At rest, the human body produces about 80-100 watts of heat. During exercise, this can increase to 300-2000 watts depending on intensity.
How is this related to exercise calories?
If you exercise at 200 watts for 30 minutes, you burn approximately 200 x 14.34 x 30 = 86,042 cal = 86 kcal (food Calories). Actual calorie burn is higher due to metabolic inefficiency.
What is the relationship between watts and joules?
1 watt = 1 joule per second. Watts measure the rate of energy transfer (power), while joules and calories measure total energy.
Why is the conversion factor 0.239006?
One calorie is defined as 4.184 joules. Since 1 watt = 1 J/s, then 1 W = 1/4.184 cal/s = 0.239006 cal/s.