Percentage calculator
Find a percentage of any number. Calculate discounts, portions and everyday percentages with precise decimal arithmetic.
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Percentage (%) | Enter percentage units: 5 means 5%, not a fraction of 0.05. |
| Of this number | Enter of this number using the definition in the method and example. |
Understanding your result
Read Percentage of your number in the units and model stated on this page. The formula result = value × percentage ÷ 100 defines the relationship; measurement accuracy and model applicability are separate from numerical precision.
Common mistakes
- Mixing input units or changing the physical meaning of a variable without changing the model.
Check your calculation
- Use the worked example as a known reference case, then change one input at a time and check the direction and units of the response.
How much is a percentage of a number?
Enter the percentage and the whole amount to find the corresponding part. For a discounted selling price, use the discount calculator, which also subtracts the saving.
Common uses
- Find the percentage share of a total.
- Work out a percentage-based discount amount.
How it works
Divide the percentage by 100, then multiply by the base value. A percentage above 100 produces more than the original amount. Negative inputs retain their mathematical sign.
Worked example
15% of 200 = 15 ÷ 100 × 200 = 30.