HomePercentage Calculator
Percentage Calculator
Five types of percentage problems — all solved as you type.
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What is X% of Y?

What is
%
of
30
15% × 200 = 30

X is what % of Y?

is what % of
15%
30 ÷ 200 × 100 = 15%

Percentage change

From
to
+25%
(125 − 100) ÷ 100 × 100 = 25% increase

X out of Y as a percentage

out of
15%
45 ÷ 300 × 100 = 15%

Add or remove a percentage

%
120
100 + 20% = 100 + 20 = 120
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Quick reference
10% of XX ÷ 10
25% of XX ÷ 4
50% of XX ÷ 2
75% of XX × 0.75
200% of XX × 2

🛍️ Common uses

  • Sales tax: price × 1.08
  • 15% tip: bill × 0.15
  • 20% off: price × 0.80
  • Grade: score ÷ total × 100
  • Markup: cost × (1 + markup%)
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How to calculate percentages

A percentage expresses a number as a fraction of 100. Use the five calculators above to solve any percentage problem — from finding what 15% of $200 is, to calculating how much a price changed, to working out a test score.

Percentage change formula

% change = [(New − Old) ÷ |Old|] × 100. Positive = increase, negative = decrease.

Basic percentage formula

To find X% of Y: multiply Y by X, then divide by 100. Example: 15% of 200 = (200 × 15) ÷ 100 = 30.

Common questions

For X% of Y: multiply X × Y then divide by 100. On most calculators: enter Y, press ×, enter X, press %, press =. Example: 15% of 80 → 80 × 15% = 12.
Divide the sale price by (1 − discount). If something costs $80 after a 20% discount: $80 ÷ 0.80 = $100 original price.
Going from 2% to 3% is a 1 percentage point increase, but a 50% relative increase. Percentage points are absolute; percentages are relative. This matters in finance, polls, and economics.
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