Percentage Calculator
Six percentage calculators in one place: percent of a number, what percent, reverse percentage, percentage change, increase or decrease, and difference. Every answer shows the formula with your numbers plugged in.
How to use the percentage calculator
Pick The Question
Six cards cover the common percentage questions, from "what is 15% of 200" to percentage change and difference.
Type Your Numbers
Fill in the blanks in the sentence. The answer updates on every keystroke, no calculate button.
Check The Math
The formula appears under each answer with your numbers plugged in, and one click copies the result.
Every Percentage Question, Answered With The Work Shown
Percentages trip people up because the same word covers six different questions. “What is 15% of 200” is one calculation, “30 is what percent of 200” is another, and “the price went from 40 to 50, what is the change” is a third. Most calculators make you figure out which mode you need. This one lays all six out as plain sentences, so you pick the one that reads like your question and fill in the blanks.
The part most tools skip is the work. Under every answer the calculator prints the exact formula with your numbers plugged in, like 30 ÷ 200 × 100 = 15%. That matters when you are checking homework, explaining a discount to a customer, or making sure a spreadsheet formula is right. Percentage change is signed and color coded so an increase and a decrease never get confused, and percentage difference uses the symmetric definition, the gap divided by the average of the two values.
Everything runs on your device with no signup and no limits. If you work with money percentages often, the GST and discount calculators handle tax-inclusive prices and sale pricing, and the EMI calculator covers loan math.
Why Use Our Percentage Calculator?
Six Calculators In One
Percent of a number, what percent, reverse percentage, percentage change, increase or decrease by a percent, and percentage difference.
Live Answers
Results update as you type in any field. There is no calculate button and no page reload.
Shows The Formula
Every answer prints the formula with your numbers in it, like (50 − 40) ÷ 40 × 100 = +25%, so you can follow the math or copy it into homework.
Increase And Decrease Aware
Percentage change is signed and color coded, green for an increase and red for a decrease, so a drop never reads like a gain.
One-Click Copy
Each result has its own copy button, formatted and ready to paste into a sheet, a message, or an assignment.
Private And Free
All six calculators run on your device. No signup, no limits, and nothing you type is sent anywhere.
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Frequently Asked Questions
Common questions about calculating percentages.
How do I calculate a percentage of a number?
Divide the percent by 100 and multiply by the number, so 15% of 200 is 15 ÷ 100 × 200 = 30. In the tool, type both numbers into the "percent of a number" card and the answer appears instantly with that formula shown underneath.
How do I find what percent one number is of another?
Divide the first number by the second and multiply by 100. For example, 30 is 30 ÷ 200 × 100 = 15% of 200. The "what percent" card does this live and prints the division so you can check it.
How do I calculate percentage increase or decrease?
Subtract the old value from the new one, divide by the old value, and multiply by 100. Going from 40 to 50 is (50 − 40) ÷ 40 × 100 = +25%. The calculator signs and colors the result, green for an increase and red for a decrease.
What is the difference between percentage change and percentage difference?
Percentage change compares a new value against an old one, so direction matters and the answer is signed. Percentage difference compares two values with no order, dividing the gap by their average, so 40 vs 60 is a 40% difference either way. The tool has a separate card for each.
How do I reverse a percentage?
Divide the part by the percent expressed as a decimal. If 30 is 15% of some number, that number is 30 ÷ 0.15 = 200. The "reverse percentage" card handles this, which is useful for working back to an original price before a discount or tax.
Is the percentage calculator free?
Yes, completely free with no signup and no usage limit. All six calculators run in your browser on your own device, so nothing you enter is sent to a server.