Power Conversion Calculator
Convert among units of power and heat flow. (IT) = International Table, (th) = Thermochemical.
| Unit | Symbol | Value in Watts | Conversion Factor |
|---|
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Power Conversion Calculator
Power conversion calculators simplify switching between units like watts, BTU per hour, and horsepower. Whether you’re an engineer tweaking HVAC systems or a hobbyist building electronics, accurate conversions prevent costly errors. This in-depth guide breaks down how these tools work, provides a ready-to-use conversion table, and shares practical tips to handle power and heat flow units effortlessly.
In everyday scenarios, you might need to convert boiler horsepower to kilowatts for energy efficiency audits or erg per second to joules for scientific calculations. We’ll cover the basics, step-by-step methods, and common pitfalls to ensure your results are spot-on.
Understanding Power and Heat Flow Units
Power measures the rate of energy transfer, typically in watts (W). Heat flow, a subset, often uses units like BTU (British Thermal Units) or calories. These terms pop up in industries from automotive to renewable energy.
Key distinctions:
- Power units focus on mechanical or electrical work, like horsepower in engines.
- Heat flow units track thermal energy movement, such as cal/s in thermodynamics.
Grasping these helps align with real-world applications. For instance, converting BTU/h to watts is crucial for sizing air conditioners. If you’re dealing with related measurements, check out our comprehensive unit conversions hub for seamless switches across categories.
How to Convert Units of Power and Heat Flow
Conversions rely on multiplication factors. The formula is straightforward: S * C = E, where S is your starting value, C the conversion factor, and E the end result.
To convert to watts from any unit, multiply by the factor listed for that unit. Example: 50 BTU/h (IT) * 0.2930711 = 14.653555 W.
Reversing it? Divide by the factor or multiply by its reciprocal. So, 14.653555 W / 0.2930711 = 50 BTU/h.
For direct conversions between two non-watt units, divide the starting unit’s factor by the target unit’s factor. Say, from BTU/h (th) to cal/s (th): 0.2928751 / 4.184 ≈ 0.069998829. Multiply your value by this.
This method beats manual calculations, especially with complex units like foot-pound-force per minute. Always double-check factors for precision—small errors amplify in large-scale projects.
Power Conversion Calculator Table: Key Units and Factors
Below is a detailed table of common power and heat flow units. Use the “Multiply By” column to convert to watts. For accuracy, perform operations as noted (e.g., divisions for time-based units).
| Unit | Symbol | To Convert to Watts (W) | Multiply By (W / Unit) |
|---|---|---|---|
| BTU [IT] per hour | BTUIT/h | watt | 0.2930711 |
| BTU [IT] per minute | BTUIT/min | watt | 0.2930711 * 60 |
| BTU [IT] per second | BTUIT/s | watt | 0.2930711 * 60 * 60 |
| Calorie [IT] per hour | calIT/h | watt | 4.1868 / 60 / 60 |
| Calorie [IT] per minute | calIT/min | watt | 4.1868 / 60 |
| Calorie [IT] per second | calIT/s | watt | 4.1868 |
| BTU [th] per hour | BTUth/h | watt | 0.2928751 |
| BTU [th] per minute | BTUth/min | watt | 0.2928751 * 60 |
| BTU [th] per second | BTUth/s | watt | 0.2928751 * 60 * 60 |
| Calorie [th] per hour | calth/h | watt | 4.184 / 60 / 60 |
| Calorie [th] per minute | calth/min | watt | 4.184 / 60 |
| Calorie [th] per second | calth/s | watt | 4.184 |
| Cheval-vapeur | cv | watt | 735.49875 |
| Erg per hour | erg/h | watt | 0.0000001 / 60 / 60 |
| Erg per minute | erg/min | watt | 0.0000001 / 60 |
| Erg per second | erg/s | watt | 0.0000001 |
| Foot-pound-force per hour | ft·lbf/h | watt | 1.355818 / 60 / 60 |
| Foot-pound-force per minute | ft·lbf/min | watt | 1.355818 / 60 |
| Foot-pound-force per second | ft·lbf/s | watt | 1.355818 |
| Foot-poundal per hour | ft·pdl/h | watt | 0.04214011 / 60 / 60 |
| Foot-poundal per minute | ft·pdl/min | watt | 0.04214011 / 60 |
| Foot-poundal per second | ft·pdl/s | watt | 0.04214011 |
| Horsepower (550 ft · lbf/s) | hp | watt | 745.6999 |
| Horsepower (boiler) | hp | watt | 9809.5 |
| Horsepower (electric) | hp | watt | 746 |
| Horsepower (metric) | hp | watt | 735.49875 |
| Horsepower (mechanical) | hp | watt | 745.7 |
| Horsepower (water) | hp | watt | 746.043 |
| Joule per hour | J/h | watt | 1 / 60 / 60 |
| Joule per minute | J/min | watt | 1 / 60 |
| Joule per second | J/s | watt | 1 |
| Kilowatt | kW | watt | 1000 |
| Pferdestarke | PS | watt | 735.49875 |
| Watt | W | watt | 1 |
This table covers international (IT) and thermochemical (th) variants, ensuring versatility for global standards.
Step-by-Step Examples Using the Power Conversion Calculator
Let’s apply the table practically.
Example 1: BTU/h to Watts Start with 100 BTU/h (IT). Multiply by 0.2930711: 100 * 0.2930711 = 29.30711 W. Ideal for estimating appliance power draw.
Example 2: Horsepower to Kilowatts For mechanical horsepower, first to watts: 5 hp * 745.7 = 3728.5 W. Then to kW: 3728.5 / 1000 = 3.7285 kW. Useful in automotive specs.
Example 3: Calorie per Second to Joules per Second cal/s (IT) factor is 4.1868 W/cal/s. Since J/s = W, 10 cal/s * 4.1868 = 41.868 W (or J/s).
These examples highlight efficiency. For thermal-related tasks, explore our temperature unit converter to pair with heat flow calculations.
Common Power Units Explained: Watts, BTU, Horsepower, and Beyond
- Watts (W): The SI unit, equaling one joule per second. Base for most conversions.
- BTU per Hour (BTU/h): Measures heat energy, common in HVAC. IT vs. th differs slightly—use the right one for accuracy.
- Horsepower (hp): Varies by type (mechanical, electric). Metric hp (PS or cv) is about 735 W, while imperial is 746 W.
- Calories (cal): Thermochemical or international; per second aligns closely with watts.
- Ergs and Foot-Pounds: Micro-units for precise lab work or mechanical engineering.
Tips for Accurate Power Conversions in Real-World Applications
- Verify Standards: US projects often use IT, while scientific ones prefer th.
- Account for Time: Hourly units need division by 3600 for seconds.
- Use Tools Wisely: Online calculators automate this, but knowing manual methods catches errors.
- Precision Matters: Round factors appropriately—e.g., 0.293 for quick estimates, full digits for engineering.
If conversions involve pressure in fluid systems, our pressure conversion tool integrates well with power calcs.
Why Use a Power Conversion Calculator?
Manual errors waste time. A reliable calculator ensures compliance in fields like renewable energy or manufacturing. Plus, it handles obscure units like pferdestarke without hassle.
In 2025, with rising energy demands, tools like this support sustainable designs. Pair it with efficiency audits for optimal results.
Frequently Asked Questions About Power Conversion
What’s the difference between power and energy?
Power is energy per time (e.g., W = J/s). Convert energy units separately.
How do I convert kilowatts to horsepower?
Divide kW by 0.7457 for mechanical hp.
Are there apps for this?
Yes, but web-based ones offer more units without downloads.
This guide equips you for any power or heat flow challenge. Dive in and convert confidently.
References
The National Institute of Standards and Technology (NIST) – The NIST Guide for the use of the International System of Units – Appendix B, subsections B.8 Factors for Units Listed Alphabetically and B.9 Factors for units listed by kind of quantity or field of science.
Lide, David R., Daniel (Editor-in-Chief). CRC Handbook of Chemistry and Physics, 89th Edition New York, NY: CRC Press, p. 1-28, 2008.
Wikipedia contributors. “Conversion of units” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, last visited 16 Nov. 2010.