Calculate any
percentage instantly.
Find the percentage of a number, percentage change, percentage difference, and reverse percentages. Four calculators in one — accurate, instant, and completely free.
Four calculators, one tool.
Pick a Mode
Choose from percent of, percent change, percent difference, or reverse percent. Each tab reveals its own inputs.
Enter Your Values
Type the numbers you have. Every field updates the result in real time — no button to press.
Read the Result
Get the answer, the formula used, and secondary values like the difference or total. Copy with one click.
Percentage formulas.
The four core percentage formulas used by this calculator — handy for checking your work by hand.
🎯 Percent of a Number
result = (percent ÷ 100) × number
Find what a given percentage of a value is. Example: 25% of 80 = (25 ÷ 100) × 80 = 20.
📈 Percent Change
change% = ((new − old) ÷ old) × 100
Measure an increase or decrease from an original value. Positive = increase, negative = decrease.
↔️ Percent Difference
diff% = (|a − b| ÷ ((a + b) ÷ 2)) × 100
Compare two values without direction, using their average as the base. Useful in science and statistics.
🔁 Reverse Percent
original = final ÷ (1 − percent ÷ 100)
Find the original value before a percentage was applied. Example: $60 after 25% off → 60 ÷ 0.75 = $80.
Frequently Asked Questions.
To find the percentage of a number, multiply the number by the percentage and divide by 100. For example, 25% of 80 = (25 × 80) ÷ 100 = 20. Our calculator does this instantly.
Percentage change = ((New Value − Old Value) ÷ Old Value) × 100. A positive result is an increase, a negative result is a decrease.
Percentage change compares a new value to an original value (directional). Percentage difference compares two values without direction, using the average of the two as the base: |A − B| ÷ ((A + B) ÷ 2) × 100.
Use the reverse percentage formula: original = final ÷ (1 − discount ÷ 100). For example, if a $60 item is 25% off, the original price is 60 ÷ 0.75 = $80.
Percentage increase = ((New Value − Original Value) ÷ Original Value) × 100. Example: from 50 to 65 → ((65 − 50) ÷ 50) × 100 = 30% increase.
Yes, the percentage calculator is 100% free with no signup, no downloads, and no hidden costs. Use it as often as you like.