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Percentage Calculator

Percentages appear everywhere: discounts, exam marks, tax, tips and growth rates. This calculator handles the three most common questions: what is X percent of a number, what percent one number is of another, and by what...

How it works Report a problem

Master Percentage Suite

Omnichannel ratio engine with deep-variance intelligence and scalar mapping

Proportion
Ratio Finder
Variance
%
Extracted Functional Mass
100
Occupancy Scale 20%
Logic: V = (P/100) * B
Calculation: (20 / 100) * 500 = 100
Relative Density %
25%
Logic: P = (T / G) * 100
Calculation: (50 / 200) * 100 = 25%
Delta (Variance)
+50%
GROWTH DETECTED
Logic: Δ = ((C - H) / H) * 100
Calculation: ((150 - 100) / 100) * 100 = 50%

About the Percentage Calculator

Percentages appear everywhere: discounts, exam marks, tax, tips and growth rates. This calculator handles the three most common questions: what is X percent of a number, what percent one number is of another, and by what percent a value has changed.

How to use the Percentage Calculator

  1. To find a percentage of a number, enter the percentage and the number it applies to.
  2. To find what percent one number is of another, enter the part and the whole.
  3. To find a percentage change, enter the old value and the new value.
  4. Press Calculate in the section you are using.

Formula and method

Percentage of a number: Result = (Percent ÷ 100) × Number

Percent one number is of another: Percent = (Part ÷ Whole) × 100

Percentage change: Change % = ((New − Old) ÷ Old) × 100

Worked example

15% of 240 = 0.15 × 240 = 36. 45 is (45 ÷ 240) × 100 = 18.75% of 240. A price rising from 80 to 100 is a change of (100 − 80) ÷ 80 × 100 = +25%.

Tips

  • A percentage increase followed by the same percentage decrease does not return you to the start: +25% then −25% ends at 93.75% of the original.
  • Percentage points and percent are different. Going from 10% to 12% is a rise of 2 percentage points but 20 percent.
  • To find the original price after a discount, divide by (1 − discount).

Frequently asked questions

How do I calculate a percentage in my head?
Find 10% by moving the decimal one place, then build up. For 15% of 240: 10% is 24, 5% is 12, so 15% is 36.
How do I calculate percentage increase?
Subtract the old value from the new value, divide by the old value and multiply by 100.