Percentage Calculator

The three percentage formulas

• X% of Y = X ÷ 100 × Y  →  15% of 200 = 30
• X as a percent of Y = X ÷ Y × 100  →  30 of 150 = 20%
• Change from X to Y = (Y − X) ÷ X × 100  →  80 → 100 = +25%

Frequently asked questions

How do I calculate a discount?

Use the first calculator: 25% of the €60 price is €15, so you pay €45. Or multiply the price by (100 − discount)/100 directly.

Why is percent change asymmetric?

Because the base changes: going 80 → 100 is +25%, but 100 → 80 is −20%. The change is always measured relative to the starting value.

What about percentage points?

If an interest rate rises from 4% to 5%, it's up 1 percentage point but 25 percent. Points are absolute; percent is relative.