Percentage Calculator

Calculate percentages, percentage increase/decrease, and percentage of a number.

Common Percentage Calculations

Percentage Common Use Decimal Fraction
10%Sales tax, tip0.11/10
25%Quarter of a value0.251/4
50%Half of a value0.51/2
75%Three quarters0.753/4
100%The whole amount11/1

About Percentages

A percentage is a number expressed as a fraction of 100. The symbol % is used to indicate percentages. For example, 50% means 50 out of 100, or 50/100, which can be simplified to 1/2.

Percentage Formulas

  • Percentage of a number: (Percentage × Value) ÷ 100
  • Percentage increase/decrease: [(New Value - Original Value) ÷ Original Value] × 100
  • Converting percentage to decimal: Percentage ÷ 100
  • Converting percentage to fraction: Percentage / 100 (then simplify)