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 microwatt?
A microwatt is a unit of power equal to one millionth of a watt. It is used in ultra-low-power electronics, energy harvesting systems, biosensors, and precision scientific instrumentation.
Real-world uses
Microwatts measure the power of radio frequency (RF) signals received by antennas, ultra-low-power IoT sensors, cardiac pacemaker power consumption, and energy-harvesting devices. Satellite receivers may work with signals in the nanowatt to microwatt range. Wearable health monitors often operate at a few microwatts.
History
Microwatts became a meaningful engineering unit as semiconductor miniaturisation through the 1970s–2000s enabled ultra-low-power circuit design. The proliferation of wireless sensors, implantable medical devices, and battery-free energy harvesting systems in the early 21st century made µW-level power budgeting essential.
Common mistakes
Confusing microwatts (µW) with milliwatts (mW)—a difference of 1,000×. In RF engineering, power is often expressed in dBm (decibels relative to 1 mW), which requires knowing that 0 dBm = 1 mW = 1,000 µW, and negative dBm values correspond to sub-milliwatt levels.
When is this conversion used?
Converting between kilocalorie per hour and microwatt 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 = 1,163,000 microwatt
1 microwatt = 0.000001 watt
How to convert kilocalorie per hour to microwatt
To convert kilocalorie per hour to microwatt, multiply the value by 1,163,000.
To convert microwatt back to kilocalorie per hour, multiply by 8.598452e-07.
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 microwatt
| kilocalorie per hour | microwatt |
|---|---|
| 0.1 | 116,300 |
| 0.5 | 581,500 |
| 1 | 1,163,000 |
| 2 | 2,326,000 |
| 5 | 5,815,000 |
| 10 | 11,630,000 |
| 25 | 29,075,000 |
| 50 | 58,150,000 |
| 100 | 116,300,000 |
| 250 | 290,750,000 |
| 500 | 581,500,000 |
| 1,000 | 1.163000e+09 |
Common values
| kilocalorie per hour | microwatt | |
|---|---|---|
| LED light bulb | 8.59845228 kilocalorie per hour | 10,000,000 microwatt |
| Desktop computer | 257.95356836 kilocalorie per hour | 300,000,000 microwatt |
| Microwave oven | 859.84522786 kilocalorie per hour | 1.000000e+09 microwatt |
| Small car engine | 64,488.39208942 kilocalorie per hour | 7.500000e+10 microwatt |
| Wind turbine (large) | 2,579,535.68357696 kilocalorie per hour | 3.000000e+12 microwatt |
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.