How do you calculate percentage increase?
Subtract the old value from the new value, divide by the absolute old value, and multiply by 100.
Percentage Increase Calculator
Measure growth from an old value to a new one, or apply a percent increase to find the new amount.
Choose an increase mode
Compare two values, or raise a starting value by a percent.
About this calculator
How to use Percentage Increase Calculator, plus the formulas and logic behind the results.
Tool description
Percentage increase shows how much a quantity grew relative to its starting point, or projects a new value after a percent markup.
How to use
- Select from-to mode or increase-by-percent mode.
- Enter the old value and either the new value or the percent.
- Select Calculate to view the increase.
- Use Clear to restore the sample numbers.
Formulas & reference
From→to: ((new − old) ÷ |old|) × 100By percent: new = old × (1 + percent ÷ 100)Increase amount = new − old
Increase examples
- 80 → 100 is a 25% increase
- Increase 200 by 10% → 220
- Increase amount = new − old
- Base of zero cannot measure percent increase
Calculation logic
From-to mode divides the change by the absolute old value. By-percent mode scales the old value by (1 + p/100). A zero old value is blocked in from-to mode.
If the new value is smaller than the old value in from-to mode, the result is a negative increase (a decrease).
Percentage Increase Calculator FAQ
Common questions about this calculator and how to use the results.
How do you increase a number by a percent?
Multiply by (1 + percent/100). For example, 200 × 1.10 = 220 for a 10% increase.
What if the value went down?
From-to mode returns a negative percentage, indicating a decrease.
Can the old value be negative?
Yes. The formula uses the absolute old value in the denominator for stability.
Is markup the same idea?
A markup is often an increase-by-percent applied to a cost or price.
Why can’t old be zero in from-to mode?
Dividing by zero is undefined, so percent increase from zero is not defined.