Percentages and fractions are related concepts in the world of mathematics. Each concept represents a piece of a larger unit. Fractions may be converted into percentages by first converting the fraction into a decimal number. You may then perform the necessary mathematical function, such as addition or subtraction, before converting the final decimal number into a percentage.

Use the calculator to divide the numerator (top number) of the first fraction by the denominator (bottom number) of the first fraction. Write this decimal number down.

Divide the numerator of the second fraction by the denominator of the second fraction and write this decimal number down.

Perform the required mathematical function with the two decimal numbers. For example, if you are adding 1/4 and 1/5 together, these would convert into 0.25 and 0.20 respectively. Add 0.25 to 0.20 to get 0.45.

Multiply the resulting decimal number by 100 to obtain the percentage. For the example above, 0.45 multiplied by 100 equals 45 percent.