Percentage Calculator (% of, Increase, Decrease, Difference)
Four percentage tools in one: find a percentage of a number, work out what percentage X is of Y, calculate percentage increase or decrease, and apply a percentage change to any value.
e.g. What is 15% of 200?
Result
15% of 200
30
As a decimal
0.15
Concept
A percentage is a ratio expressed out of 100 — the Latin per centum means "per hundred." So 15% means 15 out of every 100, or the fraction 15/100 = 0.15.
Percentage change is a relative measure, not an absolute one. A rise of ₹500 is a 50% increase when the starting price is ₹1,000, but only 0.05% when the starting price is ₹1,000,000. Always compare the difference to the original value.
To apply a percentage change, use the multiplier form: multiply the original by (1 + P/100). A 20% increase means multiplying by 1.20; a 15% decrease means multiplying by 0.85. This is more reliable than adding the percentage amount separately, especially when chaining multiple changes.
Formula
Variables
P- The percentage value (e.g. 15 for 15%).
Base / Y- The reference or whole quantity the percentage is applied to.
X- The part being compared to Y when finding what percentage X is of Y.
Old / New- The before and after values for calculating percentage change.