Find X% of Y, measure percentage change, or see what percent one number is of another. Instant, accurate, and mobile-friendly.
Use this percentage calculator to find X% of Y, measure percentage increase or decrease, and determine what percent one number is of another. Designed for finance, shopping, grading, and everyday math.
Get instant percentage calculations without manual math or spreadsheets.
Handle percent of a number, percentage change, and reverse percentage in one place.
See the underlying formulas so you can verify and learn the math.
Basic formula: Percentage = (Part / Whole) × 100
Find X% of Y: Result = (X / 100) × Y
Percentage change: ((New − Original) / Original) × 100
Decimal to percent: multiply by 100 (0.25 → 25%).
Mental math shortcuts: 10% is one decimal left; 50% is half; 25% is one-quarter.
Common pitfall: use the original value as the base when measuring increases or decreases.
Set the percentage, base value, original and new values, or part and whole.
Press Calculate to compute all percentage scenarios at once.
See percent of a number, percentage change, and what percent one number is of another.
Find sale prices, tax amounts, and tips instantly.
Measure returns, rate impacts, and revenue changes.
Calculate scores, completion rates, and performance deltas.
Use ((New − Original) / Original) × 100. Positive is an increase; negative is a decrease.
Percentage change is undefined when the original is zero, so the tool leaves it blank to avoid misleading results.
Yes. Enter a part and whole to see what percent one number represents of another.
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Compute X% of Y, percentage change, and what percent one number is of another in one place.
View the outputs for each percentage calculation type.
X% of Y
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Result of 0% of 0
Percentage change
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From 0 to 0
What percent is X of Y
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0 out of 0
Basic formula
Percentage = (Part / Whole) × 100
Increase/Decrease
Change = ((New − Original) / Original) × 100
Find X% of Y
Result = (X / 100) × Y