Percentages, made simple.
Quick answers for discounts, everyday math, and changes over time.
How the calculations work
A percentage of a number
Divide the percentage by 100, then multiply by the number. For example, 15% of 200 is 30. A 15% discount on $200 saves $30.
One number as a percentage of another
Divide the first number by the total, then multiply by 100. For example, 25 out of 200 is 12.5%. The total cannot be zero.
Percentage increase or decrease
Subtract the original value from the new value, divide by the original value, then multiply by 100. Going from 80 to 100 is a 25% increase; going from 100 to 80 is a 20% decrease. The original value cannot be zero. Negative original values can produce results that need extra interpretation.
Results are rounded for display to a maximum of six decimal places.