Percentage Calculator
Calculate percentages, proportions, and changes in three calculation modes, for commission calculations, discounts, or percentage shifts. GDPR-compliant.
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How to use this tool (video)
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Percentage Calculator: Calculate Percentages Quickly
Calculate percentages for discounts, tax, interest, statistics, and tips. Choose a calculation type, enter the values, and see the result with the underlying formula.
Select the calculation you need, enter your values and the result appears immediately, together with the underlying formula so you can follow how it is reached.
How percentage math works
The three standard cases are solved with simple formulas:
- Find a share:
Share = value × p ÷ 100. Example: 20% of 200 = 200 × 20 ÷ 100 = 40. - Find the percentage:
p = x ÷ y × 100. Example: what percent of 200 is 40? 40 ÷ 200 × 100 = 20%. - Find the change:
Change = (new − old) ÷ old × 100. Example: from 200 to 250 is (250 − 200) ÷ 200 × 100 = a rise of 25%.
Common percentage calculations
Find a percentage of a value, determine what percentage one value is of another, or calculate the percentage change between two values. The calculator keeps the steps clear and easy to check.
Everyday examples
- Shopping: an item costs 80 and is 15% off: how much do you save? (12)
- VAT: net price 100 + 19% VAT = 119 gross.
- Salary: a salary rising from 3,500 to 3,850 is an increase of 10%.
- Tip: 10% of 45 = 4.50.
- Interest: 3.5% interest on 10,000 = 350 per year.
What to keep in mind
For the percentage change the starting value must not be zero. For "x is what percent of y" the reference value y must not be zero; the tool points this out. The calculator returns pure results without rounding or special rules.
What you can use the percentage calculator for
- Prices & discounts: quick share calculations in everyday life.
- Finance: interest, tax and salary comparisons.
- Statistics & reports: express changes between two values.
Common misconceptions about percentages
- Percent vs. percentage point: if a rate rises from 19% to 20%, that is one percentage point, but about 5.3% relative growth. They are not the same thing.
- Change is not symmetric: an increase of 50% followed by a decrease of 50% does not return to the starting value, it lands at 75% of it.
- Percentages are always relative: 50% of 8 equals 8% of 50, namely 4, which is handy for mental math.
Frequently asked questions
How do I calculate a percentage of a value?
Choose the calculation type "x % of y" and enter the percentage and the value. The calculator shows you the share immediately, for example 20 % of 200 is 40.
How do I find out what percentage one value is of another?
Use the calculation type "x is what percent of y?". This way you can find out, for example, that 40 is exactly 20 % of 200.
How do I calculate a percentage change?
With the "percentage change" type you enter the original and the new value. The calculator works out the percentage increase or decrease, for example a rise of 25 % from 200 to 250.
What do the formulas shown by the calculator mean?
For every calculation the tool displays the underlying formula. This lets you see how the result is reached and helps you learn percentage math along the way.
Can I use it to calculate VAT?
Yes. With the percentage-of-value calculation you can, for example, work out the tax share, such as 19 % VAT on a net amount. The calculator handles the math reliably.
Why does the calculator not show a change?
For the "percentage change" the starting value must not be zero. For "x is what percent of y" the reference value y must not be zero; in invalid cases the tool points this out.
What is the difference between percent and percentage point?
A percentage point is the absolute difference between two percentage values, while a percent is the relative share. If a rate rises from 19% to 20%, that is one percentage point, but about 5.3% relative growth.
Are my values stored?
No. All calculations run 100 % locally in your browser. Your entries are neither sent to a server nor stored.