Online CalcKit

Percentage Calculator

Quickly work out a tip, a discount, a price change, or a markup — five percentage tools on one page.

What is X% of Y?

18% of 50 is 9.

Results update as you type.

Formula

Each tab uses a single one-line formula:

  • % of: result = (percent / 100) × value
  • What %: percent = (part / whole) × 100
  • % change: percent = ((to − from) / from) × 100
  • Add / Subtract %: result = value × (1 ± percent / 100)
  • Reverse %: original = result / (percent / 100)

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Frequently asked questions

How do I calculate a tip?

Use the % of tab. Enter the tip rate as the percent and your bill as the value. For an 18% tip on $50, the calculator returns $9. To see the total bill including tip, switch to Add/Subtract % and add 18% to $50 — the result is $59.

How do I work out a percentage discount?

Use the Add/Subtract % tab. Enter the original price as the value, the discount as the percent, and choose 'subtract'. For example, 25% off $80 is $80 − 25% = $60, with $20 in savings.

What's the difference between percentage and percentage points?

A percentage is relative; a percentage point is absolute. Moving from a 5% interest rate to 8% is a 3 percentage-point increase but a 60% relative increase. The % change tab here works in relative terms.

How do I reverse a percentage to find the original price?

Use the Reverse % tab. If $60 represents 75% of the original price (after a 25% discount), the original was $60 ÷ 0.75 = $80.

Does this calculate sales tax?

It can — enter your sales-tax rate in the Add/Subtract % tab and choose 'add'. Because rates vary by state and locality, our dedicated Sales Tax Calculator (coming soon) will let you choose by state.