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Percentage Calculator

Pick the sentence that matches what you are trying to work out, type the two numbers, and read the answer underneath. Adding, subtracting, percent of, share of and percentage change all live in one place.

What do you want to do?

A number, plus a percentage on top.

Increaseby%

A price of 240 with 15% added becomes 276. Commas and dots both work as decimals.

Answer

276

The working

240 plus 15%

Starting number
240
15% of it
36
New number
276

How the maths works

  • · Add a % = number × (1 + percent ÷ 100).
  • · Subtract a % = number × (1 − percent ÷ 100).
  • · Percent of = number × percent ÷ 100.
  • · Share = part ÷ whole × 100.
  • · Change = (new − old) ÷ old × 100.

A 20% discount followed by 20% added back does not return the original number, because the second percentage is calculated on the smaller amount.