What is kilocalorie per hour?
Kilocalorie per hour is a unit of power expressing energy transfer as dietary calories per hour. It is used in nutrition and exercise physiology to express the rate of energy expenditure during physical activity.
Real-world uses
Kilocalories per hour (kcal/h) are used in exercise physiology to express metabolic power output (a brisk walk burns about 300 kcal/h, cycling about 500–800 kcal/h), and in HVAC engineering in Asia and Latin America to rate heating and cooling equipment, where it bridges nutritional and thermal engineering contexts.
History
The kilocalorie per hour emerged as a natural unit at the intersection of nutritional science and physiology, where metabolic rates had long been expressed in food energy per unit time. In HVAC contexts, it provided a familiar scale for countries where kilocalories were the customary energy unit before SI adoption.
Common mistakes
Confusing kcal/h (power) with kcal (energy). A person burning 300 kcal/h for 2 hours has expended 600 kcal, not 300 kcal. Also, mixing up kcal/h with kJ/h: 1 kcal/h = 4.184 kJ/h ≈ 1.163 W.
What is gigawatt?
A gigawatt is a unit of power equal to one billion watts. It is used to express the total power output of national electricity grids, large power stations, and national energy policy targets.
Real-world uses
Gigawatts describe the generating capacity of entire national grids, large hydroelectric dams (Three Gorges Dam: ~22.5 GW), and the total installed solar or wind capacity of countries. Global electricity demand is often expressed in terawatts (1,000 GW). Energy policy discussions use GW to compare national ambitions.
History
Gigawatts entered common use in discussions of national and continental electricity systems during the 20th century. As installed generation capacity in large countries reached the gigawatt scale, this unit became standard for energy policy, grid planning, and international energy statistics.
Common mistakes
Confusing GW (power) with GWh (energy). A 22 GW dam running at full capacity for one hour generates 22 GWh of energy. Also, the pop-culture reference "1.21 gigawatts" from Back to the Future is frequently cited but would equal about 1,210 MW—a large power plant.
When is this conversion used?
Converting between kilocalorie per hour and gigawatt is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region.
Worked examples
1 kilocalorie per hour = 1.163000e-09 gigawatt
1 gigawatt = 1.000000e+09 watt
How to convert kilocalorie per hour to gigawatt
To convert kilocalorie per hour to gigawatt, multiply the value by 1.163000e-09.
To convert gigawatt back to kilocalorie per hour, multiply by 859,845,227.85898542.
Measurement standards
The watt is the SI derived unit of power, defined as one joule per second (kg·m²/s³). Horsepower remains in widespread informal use, particularly in the automotive industry, but has no single universal definition across regions.
Did you know?
The human body at rest produces about 80 watts of power — roughly enough to keep an incandescent light bulb glowing. During intense exercise, a trained cyclist can sustain over 400 watts, and elite sprinters briefly exceed 2,000 watts.
Quick reference: kilocalorie per hour to gigawatt
| kilocalorie per hour | gigawatt |
|---|---|
| 0.1 | 1.163000e-10 |
| 0.5 | 5.815000e-10 |
| 1 | 1.163000e-09 |
| 2 | 2.326000e-09 |
| 5 | 5.815000e-09 |
| 10 | 1.163000e-08 |
| 25 | 2.907500e-08 |
| 50 | 5.815000e-08 |
| 100 | 1.163000e-07 |
| 250 | 2.907500e-07 |
| 500 | 5.815000e-07 |
| 1,000 | 0.00000116 |
Common values
| kilocalorie per hour | gigawatt | |
|---|---|---|
| LED light bulb | 8.59845228 kilocalorie per hour | 1.000000e-08 gigawatt |
| Desktop computer | 257.95356836 kilocalorie per hour | 3.000000e-07 gigawatt |
| Microwave oven | 859.84522786 kilocalorie per hour | 0.000001 gigawatt |
| Small car engine | 64,488.39208942 kilocalorie per hour | 0.000075 gigawatt |
| Wind turbine (large) | 2,579,535.68357696 kilocalorie per hour | 0.003 gigawatt |
Available Power units
More kilocalorie per hour conversions
- Convert kilocalorie per hour to watt
- Convert kilocalorie per hour to kilowatt
- Convert kilocalorie per hour to horsepower (mechanical)
- Convert kilocalorie per hour to megawatt
- Convert kilocalorie per hour to gigawatt
- Convert kilocalorie per hour to milliwatt
- Convert kilocalorie per hour to microwatt
- Convert kilocalorie per hour to BTU per hour
- Convert kilocalorie per hour to ton of refrigeration
Assumption: horsepower values use mechanical horsepower.