Percentage Calculator

Solve common percentage calculations: find percentages of numbers, calculate percentage increases or decreases, and reverse percentage changes.

Free to use • 4 calculation modes • Instant results

What is X% of Y?

What is

% of

Result

36.00

                (15 ÷ 100) × 240 = 36.00
              

X is what percentage of Y?

is what percent of

Result Percentage

25.00%

                (45 ÷ 180) × 100 = 25.00%
              

Percentage Increase or Decrease

From

Percentage Increase

+50.00%

                ((120 - 80) ÷ 80) × 100 = +50.00%
              

Original Value From Percentage Change

Value after change:

after a

Original Starting Value

100.00

                115 ÷ (1 + 0.15) = 100.00
              

Understanding Common Percentage Formulas

Percentages express quantities as fractions of 100. In personal finance, percentages appear everywhere from interest rates, discounts, tips, and sales tax to capital gains and investment inflation.

Key Formulas

Portion of Whole: P = (X ÷ 100) × Y
Rate of Whole: Rate % = (Part ÷ Whole) × 100
Percentage Change: Change % = ((New - Old) ÷ |Old|) × 100

Frequently Asked Questions

Why is a 50% decrease followed by a 50% increase not equal to the original? ▼

Because the base changes. If $100 drops by 50%, you have $50. A 50% increase on $50 only adds $25, leaving you at $75. To recover from a 50% loss, you actually require a 100% gain!