Increase (or decrease) a number by a percentage in one step: raises, rent adjustments, price changes, and quotes. Shows the result and the amount added.

Percentage increase calculator

Enter a starting value and the percentage to increase it by. Result = value × (1 + increase ÷ 100). Use a negative percentage to decrease instead.

Result: 2,592

Amount added: 192

Formula

result = value × (1 + increase% ÷ 100)

Example: 2,400 increased by 8%: 2,400 × 1.08 = 2,592.

Raises, rent increases, and price adjustments

This is the calculation behind “your rent goes up 4% next year” or “an 8% raise on 2,400”. Multiplying by 1 plus the percentage as a decimal does it in one step: +8% is × 1.08, +25% is × 1.25, and a 100% increase doubles the value.

A subtle trap: increases and decreases do not cancel. Adding 10% and then removing 10% leaves you at 99% of the start, because the decrease applies to the larger, already-increased number.

Increasing 2,400 by common percentages

IncreaseResult
2%2,448
4%2,496
5%2,520
8%2,592
10%2,640
15%2,760
25%3,000
100%4,800

How to use Percentage increase

  1. Enter the starting value.
  2. Enter the percentage to increase by (use a negative number to decrease).
  3. Read the result and the amount added or removed.

Example: A 2,400 rent increased by 8% becomes 2,592.

Frequently asked questions

What is the quickest way to increase a number by a percentage?
Multiply by 1 plus the percentage as a decimal: +8% is × 1.08, +25% is × 1.25. A 100% increase doubles the number.
If I increase by 10% and then decrease by 10%, am I back where I started?
No—you end at 99% of the original. The decrease applies to the larger, already-increased value, so it removes slightly more than the increase added.