Add a specified percentage of your starting amount. Enter the two values below. The result panel shows the calculation used, and the examples explain how to interpret it.
How to use the percentage increase calculator
- Identify the values required by the input labels.
- Enter percentages as whole-number rates: 15 means 15%.
- Select Calculate and read the result together with its formula.
- Check the assumptions below before applying the answer to a real situation.
Formula and method
Worked example
Increase 320 by 12.5%. The added amount is 320 × 0.125 = 40. Adding that to 320 gives 360. Using a multiplier reaches the same result: 320 × 1.125 = 360.
A 100% increase doubles the original. A 200% increase triples it, because you retain the starting amount and add twice that amount. Do not confuse “increased by 200%” with “is 200% of the original.” The latter means double.
Known rate or unknown rate?
This tool starts with a known rate and calculates the new amount. If you already have an original and a new amount but want the rate, use the percentage change calculator instead. Keeping these questions separate avoids entering a final value in a percentage field.
Example calculations
| Original | Increase | New value |
|---|---|---|
| 200 | 15% | 230 |
| 80 | 25% | 100 |
| 100 | 100% | 200 |
| 60 | 0% | 60 |
Input rules and limitations
For ordinary growth interpretations, use a positive base and nonnegative increase. The arithmetic also accepts signed inputs; a negative percentage applies a decrease. Results are not forecasts.
Display precision can be changed from two to eight decimal places. Intermediate values are not rounded, but the calculation uses standard browser floating-point arithmetic. Currency figures should be rounded according to the rules relevant to your actual transaction.
Common questions
Does the result include units?
The calculator works with numbers. Keep the same units for comparable quantities and add the appropriate unit when reporting the result.
Why does the calculator reject some inputs?
For ordinary growth interpretations, use a positive base and nonnegative increase. The arithmetic also accepts signed inputs; a negative percentage applies a decrease. Results are not forecasts.
Is my information sent to a server?
Calculator values stay in your browser. They are not submitted to the website’s server for calculation.
Where can I learn the related formulas?
Use the main percentage calculator for basic shares and wholes, or browse our guides for worked examples and common mistakes.
Choose the right comparison
Use the percentage change calculator for an original-to-new comparison, the percentage difference calculator when neither value is the baseline, and the percentage points calculator to subtract rates. You can also return to the main percentage calculator.