Percentage Calculator | Percent Change, Increase & Decrease

What is X% of Y?

Percentage (%)

Of this number

X is what % of Y?

This number (X)

Of this number (Y)

Percentage Change (Increase / Decrease)

From (original value)

To (new value)

Add or Subtract a Percentage

Starting Number

Percentage (%)

➕ Add percentage ➖ Subtract percentage

Percentage Formulas & How They Work

Every result above shows the percentage formula used so you can verify the calculation or use it in a spreadsheet. The four most common percentage calculations are:

Calculation	Formula	Example
X% of Y	(X ÷ 100) × Y	20% of 500 = 100
X is what % of Y	(X ÷ Y) × 100	75 ÷ 300 × 100 = 25%
% increase	((new − old) ÷ old) × 100	(250 − 200) ÷ 200 × 100 = 25%
% decrease	((old − new) ÷ old) × 100	(200 − 150) ÷ 200 × 100 = 25%
Add X% to Y	Y × (1 + X/100)	1000 × 1.15 = 1,150
Subtract X% from Y	Y × (1 − X/100)	1000 × 0.85 = 850

Frequently Asked Questions

The basic percentage formula to find X% of a number Y is: result = (X ÷ 100) × Y. For example, 20% of 500 = (20 ÷ 100) × 500 = 0.20 × 500 = 100. This is the most common calculation — use the "What is X% of Y?" tool above to apply it instantly.

Percentage change = ((New Value − Old Value) ÷ Old Value) × 100. If the result is positive, it's an increase. If negative, it's a decrease. Example: price went from $200 to $250. Change = ((250 − 200) ÷ 200) × 100 = 25% increase.

To remove X% from a price: Multiply the price by (1 − X/100). Example: remove 15% from $1,000 = 1,000 × (1 − 0.15) = 1,000 × 0.85 = $850. Note: this is different from removing a tax like VAT/GST from an inclusive price — use our VAT Calculator for that.