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Increase or Decrease by Percent

Increase or decrease a number by a percent. Returns the new amount and the difference.

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How to use Increase or Decrease by Percent

  1. Choose job first so the fields that apply to that job appear.
  2. Enter percent, starting amount. Leave a field blank only when the page says the value is missing.
  3. Read the result rows under the form. Errors appear in the status line. Nothing is uploaded.
  4. Rounding follows IEEE floating point in this browser unless the page says it uses integers or BigInt.

Increase or Decrease by Percent

Increase

ComputesIncrease or decrease a number by a percent. Returns the new amount and the difference.
IncludesIncrease
IncludesDecrease
Enginepercentage
UploadNone
AdviceArithmetic only

What Increase or Decrease by Percent is

Increase: X × (1 + P/100). Decrease: X × (1 − P/100). 200 increased by 15% is 230. 200 decreased by 15% is 170. A 15% decrease then a 15% increase is not the original.

The formula runs in this tab. CZNull does not receive the numbers.

How this page computes

The difference row is new amount minus start. For a restaurant check the tip calculator also splits the bill.

Entities and related jobs

Increase or decrease a number by a percent. Returns the new amount and the difference. Named features: Increase, Decrease.

See also Percentage Calculator, What Is P Percent of X, Tip Calculator, Discount Calculator, Percentage Change Calculator, Scientific Calculator.

Use cases

Markups, markdowns, and raises. Sales tax that needs a jurisdiction table is not on this page.

Limits

Invalid input appears in the status line. IEEE floating point applies unless a row says otherwise. CZNull does not receive the numbers.

Increase or Decrease by Percent questions

Does this page upload my numbers?
No. The formula runs in the page you opened. CZNull does not receive the values.
What does Increase or Decrease by Percent compute?
Increase: X × (1 + P/100).
Why is this its own URL?
Search queries name this job. Nearby modes stay on their own pages so inputs do not mix. Related calculators are linked below Increase or Decrease by Percent.
What is 200 increased by 15%?
230.
Is a 15% down then 15% up the original?
No. 100 becomes 85, then 97.75.
Can I treat the result as official?
No. Rounding and real-world rules can differ. Use the page to check the arithmetic.