Percentage Calculator
Use the Percentage Calculator for a fast estimate with clear inputs, formula guidance and related tools.
Formula / method
Multi-mode calculator for percent of a number, percent change and what percent one number is of another.
How to use
Use the stated mathematical relationship and keep signs, units and order of operations consistent.
Three common percentage problems
Calculate a percentage of a number, determine what percentage one value is of another, or measure percentage change.
What this calculator answers
The Percentage Calculator uses the requested values to calculate the requested result. The core method is Multi-mode calculator for percent of a number, percent change and what percent one number is of another.. This makes the assumptions visible so you can check whether the inputs match your situation.
How to get a useful result
Use the stated mathematical relationship and keep signs, units and order of operations consistent.
How to interpret it
The result is a mathematical value based only on the numbers entered; check domain restrictions such as division by zero, roots and logarithms.
Before relying on the number
Recheck unusual inputs, confirm units and compare the result with any official quote, statement, specification or rule that applies to the real decision. Small changes in rates, time periods or measurements can materially change some results.