Percentage
Percentage Calculator
Calculate percentages three ways: X% of Y, X is what percent of Y, and X is Y% of what number — with the formula and steps.
Part = Percent ÷ 100 × Whole
Also called percent calculator · what percent of
Math · 10 calculators
Percentage Calculators
Percent of a number, percentage change, increase, decrease, difference, percent error and reverse percentages.
Percentage
Percentage Increase Calculator
Find the percentage increase between two values, or increase a number by a given percent, with the formula.
Increase % = (New − Original) ÷ Original …
Also called percent increase · increase by percentage
Percentage
Percentage Decrease Calculator
Calculate the percent decrease from an original value to a new value, or reduce a number by a percentage.
Decrease % = (Original − New) ÷ Original …
Also called percent decrease · decrease by percentage
Percentage
Percentage Change Calculator
Calculate the percentage change between an old and new value — positive for increases, negative for decreases.
% change = (New − Old) ÷ |Old| × 100
Also called percent change · change in percentage
Percentage
Percentage Difference Calculator
Compare two values with the percentage difference formula (difference ÷ average × 100), when neither is the reference.
% difference = |A − B| ÷ ((A + B)/2) × 100
Also called percent difference · relative difference
Percentage
Percent Error Calculator
Calculate percent error between an experimental (measured) value and the true (accepted) value, as used in science labs.
% error = |Measured − True| ÷ |True| × 100
Also called percentage error · experimental error
Percentage
Reverse Percentage Calculator
Find the original value before a percentage increase or decrease — e.g. the price before tax or before a discount.
Original = Final ÷ (1 + p/100)
Also called original number before percentage · reverse percent
Percentage
Percentage of Total Calculator
Enter several amounts and see what percentage each one is of the total — ideal for budgets, votes and survey results.
Share % = item ÷ total × 100
Also called percent of total · share of total
Percentage
Percentage Point Calculator
Work out the difference between two percentages in percentage points and as a relative percent change.
pp = rate₂ − rate₁
Also called percentage points · pp difference
Percentage
Percentage to Decimal Calculator
Convert a percentage to a decimal and a fraction (and back) — e.g. 37.5% = 0.375 = 3/8.
Decimal = Percent ÷ 100
Also called percent to decimal · convert percent to decimal
Key percentage formulas
| Percentage | Part = Percent ÷ 100 × Whole · Percent = Part ÷ Whole × 100 |
|---|---|
| Percentage Increase | Increase % = (New − Original) ÷ Original × 100 |
| Percentage Decrease | Decrease % = (Original − New) ÷ Original × 100 |
| Percentage Change | % change = (New − Old) ÷ |Old| × 100 |
| Percentage Difference | % difference = |A − B| ÷ ((A + B)/2) × 100 |
| Percent Error | % error = |Measured − True| ÷ |True| × 100 |
| Reverse Percentage | Original = Final ÷ (1 + p/100) |
| Percentage of Total | Share % = item ÷ total × 100 |
| Percentage Point | pp = rate₂ − rate₁ · relative % = (rate₂ − rate₁) ÷ rate₁ × 100 |
| Percentage to Decimal | Decimal = Percent ÷ 100 |
Percentage questions
How do I calculate a percentage of a number?
Divide the percentage by 100 and multiply by the number. For example, 15% of 200 = 0.15 × 200 = 30.
Is percentage change the same as percentage difference?
No. Percentage change measures change relative to the starting value (direction matters). Percentage difference compares two values relative to their average and is always positive.
What is the difference between a percent and a percentage point?
If an interest rate rises from 4% to 5%, it rose by 1 percentage point — but by 25 percent relative to where it started.