calculators.ws
🔢

Percentage Calculator - Online Percent Calculator

Free percentage calculator for percent of a number, percent change, percent increase/decrease, and reverse percentage calculations.

Percentage Calculator

Calculate any percentage problem easily

Select the type of percentage calculation.

The first number for calculation.

The second number or percentage.

Result

Enter your values to see results

and click the "Calculate" button

What is Percentage?

Percentage (%) means 'per hundred' - it represents a fraction of 100. Percentages are used daily for discounts, interest rates, tax calculations, statistics, and much more. This calculator supports 6 different percentage operations: finding a percentage, calculating ratios, percent change, increase, decrease, and reverse percentage.

How to Use This Calculator

  1. Select the type of calculation you need
  2. Enter the first value
  3. Enter the second value or percentage
  4. Click Calculate to see the result

Percentage Formulas

X% of Y = Y × (X/100)

For percent change: ((New - Old)/Old) × 100. For increase: Value × (1 + %/100). For decrease: Value × (1 - %/100).

Frequently Asked Questions

How do I calculate a percentage?
Basic formula: Result = Number × (Percentage/100). For example, 15% of 200 = 200 × 0.15 = 30. To convert a percentage to decimal, divide by 100.
How do I find what percent one number is of another?
Formula: (Part/Whole) × 100. For example, what percent is 30 of 200? (30/200) × 100 = 15%. Divide the smaller number by the larger and multiply by 100.
How do I calculate percentage increase or decrease?
Increase: Number × (1 + Percent/100). Decrease: Number × (1 - Percent/100). For example, 20% increase: multiply by 1.20. 20% decrease: multiply by 0.80.
How do I calculate percent change?
Formula: ((New Value - Old Value)/Old Value) × 100. For example, 80 to 100: ((100-80)/80) × 100 = 25% increase. Negative result means decrease.
Why doesn't 20% increase followed by 20% decrease return to original?
Because the 20% decrease applies to the new (increased) value. 100 → 20% increase → 120 → 20% decrease → 96. Net result is 4% loss. This is the 'percentage paradox.'

Related Calculators

Fraction Calculator

Fraction-percentage conversion

VAT Calculator

Tax percentage

Discount Calculator

Sale price calculations

Tip Calculator

Tip percentage

Explore more calculators

100+ calculators for finance, health, math, and everyday life

All Calculators