Percentage Calculator
Choose whether you need the value of a percentage or the percentage of a value, then get the exact number instantly.
Frequently asked questions
What’s the difference between percent and percentage points?
Percent is a relative change, while percentage points describe an absolute difference between two percentages. For example, from 20% to 25% is +5 percentage points, which is a 25% relative increase.
How do I calculate a discount or a markup?
Use “Value of percentage” to compute a percent of a base (for example 25% of 800). For discounts, subtract that value from the base. For markups, add it.
Why doesn’t +20% and then −20% return to the original?
Because the base changes. After a 20% increase, the new base is higher, so a 20% decrease removes more in absolute terms. To undo a 20% increase, you need a 16.67% decrease.
How is rounding handled?
Percent results often produce decimals. For money or invoices, you typically round to two decimals, but for analysis you may want more precision.
Value of a percentage
Select this mode when you know the base amount and the percent you want to apply. Perfect for discounts, VAT, commissions, or margins where you only need the resulting amount.
Percentage of a value
Pick this direction when you know the base and the portion. The tool instantly shows what percentage that portion equals so you can verify invoices or budgets.
No extra clutter
Each calculation returns a single, focused result so you can copy it directly into your spreadsheet, chat, or note without additional cleanup.
Percentages: the essentials
Percentages show a value “per 100”. They’re used everywhere: discounts, interest rates, tax rates, and growth.
Basic formulas
- Percentage of a number:
value = base * (percent / 100) - Percent change:
changePercent = (new - old) / old * 100 - Reverse percentage (find the base):
base = value / (percent / 100)
Percentage points vs percent
These two are easy to mix up:
- Going from 20% to 25% is +5 percentage points.
- Relative change is +25% (because 5 is 25% of 20).
Discounts and markups
A common surprise:
- Increase by 20% and then decrease by 20% does not return to the start.
Example:
- Start 100 → +20% = 120
- 120 → −20% = 96
Rounding
For money, rounding to whole currency units is often fine. For rates, one or two decimals can be more informative.
Use the calculator to explore scenarios quickly and avoid manual mistakes.
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