Crunchify.net

Percentage Calculator

Enter any two values — click = to pick which one is calculated.

Values
%

How It Works

Enter any two of the three values — Percentage, Whole, and Part — and click the = button on the row you want calculated. The underlying relationship is always: Part = (Percentage ÷ 100) × Whole.

Worked examples:

  • Discount: 20% off $85.00 → Part = (20 ÷ 100) × 85 = $17.00 off, so you pay $68.00.
  • Sales tax: 8.5% of $45.00 → Part = 0.085 × 45 = $3.83 tax, total $48.83.
  • Test grade: 42 out of 50 → Percentage = (42 ÷ 50) × 100 = 84%.
  • Tip: 18% on a $62.50 bill → Part = 0.18 × 62.50 = $11.25 tip.
  • Percentage increase: revenue went from $200 to $250 → change = 50, Percentage = (50 ÷ 200) × 100 = 25% increase.

To find what percentage one number is of another, set Percentage as the calculated field, enter the Part and the Whole, then read the result. To reverse-engineer the original value from a percentage (e.g. a price after tax), set Whole as the calculated field.

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Frequently Asked Questions

How do I calculate a percentage of a number?

Multiply the number by the percentage and divide by 100. For example, 15% of 200 = (15 ÷ 100) × 200 = 30. Enter the Percentage and Whole above and the calculator fills in the Part automatically.

How do I find what percentage one number is of another?

Divide the Part by the Whole and multiply by 100. Example: 45 is what percent of 180? → (45 ÷ 180) × 100 = 25%. Click the = button next to Percentage, enter 45 as Part and 180 as Whole.

How do I calculate a percentage increase or decrease?

Subtract the original value from the new value to get the change, then divide the change by the original and multiply by 100. Example: price rose from $80 to $100 → change = 20, increase = (20 ÷ 80) × 100 = 25%.

How do I work backwards from a percentage to find the original number?

Divide the Part by the Percentage and multiply by 100. Example: $34 is 20% of what? → (34 ÷ 20) × 100 = $170. Set Whole as the calculated field and enter Part = 34, Percentage = 20.

What is the formula for percentage?

The core formula is: Percentage = (Part ÷ Whole) × 100. Rearranged: Part = (Percentage ÷ 100) × Whole, and Whole = Part ÷ (Percentage ÷ 100).