Percentage Calculator
NewCalculate percentages, percent change, and percent increase/decrease instantly.
Percentage calculator
Percentage Calculator
Calculate percentages, percent change, and percent increase/decrease instantly.
Solve common percentage questions instantly with live-updating percentage, ratio, change, and adjustment calculations.
Mode 1
What is X% of Y?
Result
Enter a percent and base value.
Mode 2
X is what percent of Y?
Result
Enter part and whole values.
Mode 3
Percentage increase or decrease
Result
Enter starting and ending values.
Mode 4
Adjust X by Y%
Result
Enter a value and adjustment percent.
Frequently Asked Questions
Does this update automatically or do I have to press Calculate?
It recalculates all four cards as you type. There is no separate calculate button.
Why does one percentage card show an error while the others still work?
Each mode validates its own inputs independently. For example, the percent-of-whole mode rejects a whole value of 0 without stopping the other modes from updating.
Can it handle negative values or percentage drops?
Yes. The inputs accept regular numeric values, including negatives. The change card labels the result as an increase, decrease, or no change based on the sign.
What's the difference between Percentage change and Adjust X by Y%?
Percentage change compares a starting value to an ending value. Adjust X by Y% applies a chosen increase or decrease directly to one starting number.
Does Reset restore example values?
No. Reset clears the inputs and sets the adjustment dropdown back to Increase. It does not preload sample numbers.
Related Tools
Date Difference Calculator
Calculate the exact difference between two dates in days, months, years, and more.
Math Expression Evaluator
NewEvaluate mathematical expressions safely — supports arithmetic, trig, logs, sqrt, and more.
Prime Number Tools
NewCheck if a number is prime, find primes up to N, prime factorization, and nearest prime finder.