CalcNest logo

Percentage Calculator

Solve four types of percentage problems: find X% of a number, find what percent one number is of another, calculate percent change (increase or decrease), and compute the percentage difference between two values.

e.g. What is 20% of 150?

%
Enter values above to see the result.

fFormula & How It's Calculated

X% of Y: Result = (X ÷ 100) × Y
X is what % of Y: Result = (X ÷ Y) × 100
Percent Change: Result = ((New − Old) ÷ |Old|) × 100
Percent Difference: Result = |V1 − V2| ÷ ((V1 + V2) / 2) × 100

Frequently Asked Questions (FAQ)

How do I calculate percentage?

To calculate percentage, divide the part by the whole and multiply by 100. Formula: Percentage = (Part ÷ Whole) × 100. For example, scoring 40 out of 200 gives (40 ÷ 200) × 100 = 20%.

What is 15 percent of 80?

15% of 80 is 12. Calculation: (15 ÷ 100) × 80 = 0.15 × 80 = 12. Use the 'X% of Y' tab above to calculate any similar problem instantly.

How does a percent change calculator work?

Percent change = ((New Value − Old Value) ÷ |Old Value|) × 100. A positive result is a percentage increase; negative is a percentage decrease. Example: 80 to 100 = ((100−80) ÷ 80) × 100 = 25% increase.

What is the difference between percentage change and percentage difference?

Percent change is directional — it shows how much a value changed relative to a specific starting point. Percentage difference is non-directional — it compares two values using their average as the base: |V1 – V2| ÷ ((V1+V2)/2) × 100.

What is a percentage increase calculator?

A percentage increase calculator tells you how much a value grew relative to its original. Formula: ((New − Old) ÷ Old) × 100. A price rising from £50 to £65 represents a 30% increase.

What is a percentage decrease calculator?

A percentage decrease calculator tells you how much a value fell relative to its original. If a price drops from $200 to $160, the decrease is ((200−160) ÷ 200) × 100 = 20% decrease.

How to Calculate Percentage Changes — Step-by-Step Formulas

Understanding how to calculate percentage accurately requires choosing the right formula for your scenario. Below are the four most common calculation types with worked examples.

Percentage Increase Calculator

((New − Old) ÷ Old) × 100

80 → 100: ((100−80) ÷ 80) × 100 = 25% increase

Percentage Decrease Calculator

((Old − New) ÷ Old) × 100

200 → 160: ((200−160) ÷ 200) × 100 = 20% decrease

Percent Change Calculator

((New − Old) ÷ |Old|) × 100

−50 → −25: ((−25−(−50)) ÷ 50) × 100 = 50% increase

Percentage Difference Calculator

|V1−V2| ÷ ((V1+V2)/2) × 100

40 vs 60: |40−60| ÷ 50 × 100 = 40% difference

Common Use Cases for a Percentage Calculator

  • Discounts & Sales: Calculate how much you save when a product is 30% off.
  • Tax & VAT: Work out 20% VAT on a net price or back-calculate the pre-tax amount.
  • Grade Percentage: Convert raw scores to percentages — useful alongside our GPA Calculator.
  • Salary Increase: Find the percent rise if your pay goes from £28,000 to £32,000.
  • Investment Returns: Measure ROI growth — pair with our ROI Calculator.
  • Sales Tax: Compute state or local tax — see our Sales Tax Calculator.

Percentage Calculator in Other Languages

🇩🇪 Prozentrechner (German)🇫🇷 Calculateur de pourcentage (French)🇪🇸 Calculadora de porcentaje (Spanish)🇮🇹 Calcolo percentuale (Italian)

Explore more free calculators

← All Calculators