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Add or subtract a percentage
Adjust a number upward or downward by a chosen rate.
Formula: multiply the starting number by (1 + percentage ÷ 100) to add, or (1 − percentage ÷ 100) to subtract.
FREE CALCULATOR · EVERYDAY
Increase or Decrease by Percentage
Need the price after a 20% hike, or the budget after a 15% cut? This calculator applies the percentage up or down in one step — no manual two-step math.
How the increase or decrease by percentage works
Need the price after a 20% hike, or the budget after a 15% cut? This calculator applies the percentage up or down in one step — no manual two-step math.
The formula
increase: value × (1 + rate ÷ 100) · decrease: value × (1 − rate ÷ 100)
Worked example
A $200 coat is marked down 25%. Multiply 200 by (1 − 0.25) = 0.75. The sale price is $150 — you save $50.
Where this comes in handy
- Retail: apply seasonal discounts or surcharges to any price.
- Salaries: model a 4% annual raise on current pay.
- Budgets: cut every department line by 10% at once.
- Inflation: estimate next year's costs from this year's plus 3%.
Increase or Decrease by Percentage — frequently asked questions
What is the fastest way to add 15% to a number?
Multiply by 1.15. The "1" keeps the original value and the ".15" adds the percentage — one step instead of two.
How do I subtract 20% in one step?
Multiply by 0.80. That keeps 80% of the value, which is the same as removing 20%.
What is the difference between a markdown and a discount?
They are the same idea: a reduction expressed as a percentage of the original price. "Markdown" is retail jargon; "discount" is the everyday word.
If I increase then decrease by the same percent, am I back where I started?
No — the decrease applies to the larger, already-increased value. Raising 100 by 10% gives 110; lowering 110 by 10% gives 99.
How do repeated small increases add up?
They compound: each increase applies to the new total. Three 10% raises turn 100 into about 133, not 130.