Convert a fraction to a decimal and a percent. Enter the numerator and denominator.
Usage Tip
Worth memorizing: 1/2 = 0.5, 1/4 = 0.25, 1/3 = 0.333, 1/8 = 0.125.
percent = decimal × 100
Some fractions terminate (1/4 = 0.25); others repeat (1/3 = 0.333…).
The fraction is also reduced to lowest terms.
Multiply the decimal by 100 for the percent.
A fraction is a division, so the decimal is the numerator divided by the denominator. For example, 3 over 8 is 0.375, and multiplying by 100 gives 37.5 percent. Some fractions end after a few digits, while others repeat forever, such as one third, which is 0.3333 and so on.
Decimals are convenient for calculators and measurements, while fractions are exact. If a fraction repeats, the decimal shown is rounded, so keep the fraction when exactness matters. A denominator of zero is undefined. Common conversions worth remembering are one half equals 0.5, one quarter equals 0.25, and one eighth equals 0.125.
To convert 7 over 16 to a decimal, divide 7 by 16, which gives 0.4375, or 43.75 percent. Three fifths gives 0.6 or 60 percent, and two thirds gives 0.6667 when rounded to four places, a repeating decimal that is only approximated by the display.
Drill and tool sizes are often given as fractions of an inch, so a quick conversion helps compare them with decimal sizes. Seven sixteenths of an inch is 0.4375 inch, which is slightly larger than 0.43 inch. Always keep enough decimal places for the precision your task requires.