 

Examples  

From  To  Result  
foot  inch 
12 inches  
83 degF  degC  28.333333333 degreesCelsius  
(360 * 160) ft^2  acre  1.3223140496 acres  
70.4 kg + 115 lb  lb  270.20543258 poundsmass  
(20ft + 2in) * (15ft  8in)  yd^2  32.117283951 yards^2  
16.2 + sqrt(16.2^2  4 * 3.1 * 0.7) 
1  0.27015379861  
(1/4) mile / 4.751 seconds  miles/hour  189.43380341 miles / hour  
pi (4.7 cm)^2 sin(41 deg)  mm^2 
4552.9041288 millimeters^2  
50 meters * 25 meters * 10 ft  imperial gallons  8.3808283602 * 10^5 gallonsUK  
(2000 V/m) * 35 cm * 2 elementarycharges  eV  1400 electronvolts 
Enter the units or the mathematical expression with units that you want to convert. This can be as simple as a unit name or as complex as a formula involving additions, subtractions, multiplications, divisions, powers, square roots, and scientific functions (sin, cos, tan, arcsin, arccos, arctan, sinh, cosh, tanh, log, ln, and exp). The expression entry is very flexible; try typing an expression as you would normally write it.
Expression Features  

Feature  Example 
Interpretation  
Abbreviations are supported (see the name index).  ft  foot  
m  meter  
Standard metric power prefixes are supported.  millisecond  0.001 seconds  
kilometer  1000 meters  
Scientific notation is supported 
4.2 * 10^3  0.0042  
4.2e3  0.0042  
2 * 10^3  2000  
2e3 
2000  
"^" is the power operator.  4^2  16  
mile^2  mile mile  
second^1 
1 / second  
sqrt is the square root function.  sqrt(4 m^2) 
2 meters  
sqrt(37)  (not supported)  
sin, cos, tan, arcsin, arccos, arctan, sinh, cosh, tanh, log, ln, and exp represent their respective scientific functions. A trig function argument without units is considered to be in radians but you can also use units such as deg with function arguments.  cos(pi/3) 
0.5  
cos((pi/3) rad)  0.5  
cos(60 deg)  0.5  
sin(100 grad)  1.0  
tan(800 mil)  1.0  
"*" or a space between expressions represents the multiply operator. However, if the expressions are simple and have the same dimensions, a space is treated as an addition (which is common with written expressions).  (4 * 5) grams  20 grams  
3 newtons * 2 meters  6 newton meters  
5ft 45lbf  225 foot poundsforce  
6ft 4in  6 feet + 4 inches  
2hr 37min  2 hours + 37 minutes  
Modifiers square, sq, squared, cubic, cu, cubed, and reciprocal have their normal meaning. 
square meter  meter^2  
sq yard  yard^2  
second squared  second^2  
cubic inch 
inch^3  
cu yd  yard^3  
cm cubed  centimeter^3  
reciprocal second  1 / second  
In general, a "" connecting names is treated the same as a space. If you need a subtraction operator or negative sign involving just unit names, put at least one space around the "".  kilogrammeter/second^2  kilogram meter/second^2  
kg  lb  (subtraction)  
cubicyard  yard^3  
cubic yard  (yard)^3  
Sometimes a "" is used to distinguish a unit name from an expression with the same words.  kilogramcalorie 
the unit kilocalorie  
kilogram calorie  a mass times an energy 
An expression for the "To" entry typically involves only units that are combined with multiplications, divisions, and powers. However, it is possible to use more general expressions like those for the "From" entry. Consider these special examples:
Special "To" Entry Examples  

From  To  Result  Problem Solved  
32 ft  15 in  25.6 * (15 inches)  How many 15 inch stones will fit along a 32 foot path? Answer: 25.6  
17000 miles/hour  c  2.534980383 * 10^5 speedoflightinvacuum  What fraction of the speed of light is this space ship traveling? Answer: 2.534980383 * 10^5 