Percentage Calculator
Calculate percentages five different ways: percentage of a number, percentage increase or decrease, what percent X is of Y, and percentage difference.
Runs entirely in your browser — your files are never uploaded to a server.
How It Works
1. Choose Your File
Drag & drop or select the file you want to work with.
2. Processed in Your Browser
Everything happens locally on your device — your file is never uploaded anywhere.
3. Download Your Result
Get your finished file instantly, ready to save or share.
Frequently Asked Questions
What calculations can this tool do?
Five common ones: percentage of a number, percentage increase, percentage decrease, what percent one number is of another, and percentage difference.
What's the difference between "percentage difference" and "increase/decrease"?
Increase/decrease measures change relative to a starting value. Difference compares two values relative to their average — useful when neither is clearly the "original."
Does this tool round the results?
Results are shown to four decimal places, then formatted for readability.