Percentage Increase Calculator
Calculate the new value after increasing a number by a given percentage.
About the % Increase Calculator
Percentage increases show up everywhere from raises and rent hikes to population growth and price adjustments. This calculator takes an original value and a percentage increase and returns both the new total and the dollar (or unit) amount added.
How It Works
The calculator multiplies the original value by the percentage, expressed as a decimal, to find the increase amount, then adds that increase back onto the original value to get the new total.
New Value = Original × (1 + Percent/100); Increase Amount = New Value − Original.
Worked example
Scenario: Increasing 80 by 15%.
- Increase amount: 80 × 15% = 12.
- New value: 80 + 12 = 92 (the same as 80 × 1.15).
Result: 80 increased by 15% is 92.
Understanding a percentage increase
A percentage increase is measured from the original value, so the starting number is always the reference point. This is useful for price rises, salary increases, growth targets, budgets, and quantities that move upward.
Tips and common mistakes
- Multiply by (1 + rate) for a one-step answer: 80 × 1.15 = 92.
- Two 15% increases compound to 32.25%, not 30%.
- To reverse an increase, divide by 1.15, not subtract 15%.
Assumptions & Limitations
- Assumes a single percentage increase applied once to the original value.
- Works for any unit — dollars, population, quantity — as long as the original value and percent are both provided.
- For a series of repeated increases over time (like compound growth), apply this calculation successively for each period rather than multiplying the percentages together.