Percentage Calculator
Three modes for the three most common percentage problems. Type your numbers and the answer updates instantly.
Percentage Formulas
The three most-used percentage calculations:
X% of Y = (X ÷ 100) × Y
What % is A of B = (A ÷ B) × 100
% change from A to B = ((B − A) ÷ A) × 100
Frequently Asked Questions
Multiply by 0.2 (or divide by 5). Example: 20% of 150 = 0.20 × 150 = 30. You can also find 10% first by dividing by 10, then double it.
((New − Old) ÷ Old) × 100. If a price goes from $40 to $50, the increase is ((50−40)÷40)×100 = 25%. A negative result means it decreased.
Percentage points are the arithmetic difference between two percentages. If a rate goes from 5% to 8%, that's 3 percentage points — but a 60% relative increase. The two terms are often confused; "percentage points" is for absolute differences between rates.
To find the original value before a percentage increase or decrease: Original = Final ÷ (1 + rate). Example: a price after 20% VAT is $120. Original = 120 ÷ 1.20 = $100. Use the "% change" mode and work backwards to verify.