Power and Heat Flow Conversion Calculator

Convert Power and Heat Flow
Value to Convert:

About this converter

Convert among units of power and heat flow. (IT) = International Table, (th) = Thermochemical

How to Convert Units of Power and Heat Flow

Conversions are performed by using a conversion factor. By knowing the conversion factor, converting between units can become a simple multiplication problem:

S * C = E

Where S is our starting value, C is our conversion factor, and E is our end converted result.

To simply convert from any unit into W, for example, from 50 BTU/h, just multiply by the value in the right column in the table below.

50 BTU/h * 0.2930711 [ (W) / (BTU/h) ] = 14.653555 W

To convert from W into units in the left column divide by the value in the right column or, multiply by the reciprocal, 1/x.

14.653555 W / 0.2930711 [ (W) / (BTU/h) ] = 50 BTU/h

To convert among any units in the left column, say from A to B, you can multiply by the factor for A to convert A into W then divide by the factor for B to convert out of W.  Or, you can find the single factor you need by dividing the A factor by the B factor.

For example, to convert from BTU/h (th) to cal/s (th) you would multiply by 0.2928751 then divide by 4.184.  Or, multiply by 0.2928751/4.184 = 0.069998829. So, to convert directly from BTU/h (th) to cal/s (th) you multiply by 0.069998829.

Table of Power and Heat Flow Conversions

Note that you must first complete the operations in the Multiply By column in order to have the correct factor.  For example, converting calorie per hour (IT) to watts, 4.1868/60/60 is 4.1868 divided by 60, divided by 60 which is equal to 0.001163.  They were left in this form so that you could calculate a more accurate conversion factor.

Units, symbols and conversion values
used in this power and heat flow calculator
To Convert from
and Convert to
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/sec 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 (U.K.) 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


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.


Cite this content, page or calculator as:

Furey, Edward "Power Conversion Calculator" From http://www.CalculatorSoup.com - Online Calculator Resource.