Percentage calculator
What do you want to work out?
What is P% of X?
Y is P% of what?
Y is what percent of X?
Percentage change (old → new)
Increase a number by P%
Decrease / discount by P%
Number X (the whole)
Percentage P
%
Part Y
Percentage P
%
Part Y
Whole X
Old value (starting value)
New value
Starting value
Increase
%
e.g. 20 for 20% VAT or a 20% tip
Starting value
Decrease / discount
%
Result
JavaScript is required for the calculation.
Result
30
Difference from the starting value
–
Working
Formula: part = whole × P ÷ 100
Substitute: part = 200 × 15 ÷ 100
Answer: 15% of 200 is 30.