Percentage Calculator
A percentage of a number, what percentage, percentage increase/decrease and adding/subtracting a percentage — four calculations in one tool.
What Do You Want to Calculate?
You can use either a comma or a dot for decimals.
What Is a Percentage?
A Percentage is a share of a whole divided into a hundred parts. "15%" means "fifteen parts out of a hundred". In everyday life, discounts, price rises, interest, tax and growth rates are all expressed as percentages, so knowing the four basic percentage operations makes your work significantly easier.
Percentage Formulas
| What do you want to find | Formula | Example |
|---|---|---|
| A percentage of a number | Number × Percentage / 100 | 15% of 200 = 30 |
| What percentage it is | Part / Whole × 100 | 30 is %15 of 200 |
| Percentage change | (New − Old) / Old × 100 | 200 → 250 = 25% increase |
| Adding a percentage | Number × (1 + Percentage/100) | 200 + %15 = 230 |
| Subtracting a percentage | Number × (1 − Percentage/100) | 200 − %15 = 170 |
The Most Common Percentage Mistake
If you apply a 20% discount to an amount and then a 20% increase, you don't get back to the starting price:
- ₺200 − 20% = ₺160
- ₺160 + 20% = ₺192 (not ₺200!)
The reason is simple: the second percentage is applied to a smaller base. The same logic holds for percentage increases and decreases — which number is the base changes the result entirely.
Where Do Percentages Show Up in E-Commerce?
- Discounts: Work out the campaign price and the customer's saving with the discount calculator.
- VAT: To convert 20%, 10% or 1% between inclusive and exclusive, use the VAT calculator.
- Profit margin: Profit as a share of sales and profit as a share of cost give different results — you can see the distinction in the profit margin calculator.
- Marketplace commission: Calculate the percentage taken by Trendyol, Hepsiburada and similar platforms with the commission calculator.
You'll find all the calculators on the free tools page.
Frequently Asked Questions
How do you calculate a percentage?
Result = Number × Percentage / 100. For example, 15% of 200 = 200 × 15 / 100 = 30.
What percentage is one number of another?
Rate = (Part / Whole) × 100. So 30 is (30/200) × 100 = 15% of 200.
How do you calculate a percentage increase or decrease?
Change = (New − Old) / Old × 100. From 200 to 250 is a 25% increase; from 250 to 200 is a 20% decrease.
How do you add a percentage to an amount?
To add: Number × (1 + Percentage/100); to subtract: Number × (1 − Percentage/100). Adding 20% to 200 gives 240; subtracting gives 160.
Does a 20% increase after a 20% discount restore the original price?
No. 200 → 20% off = 160; 160 → 20% up = 192. The second percentage applies to a smaller base.
Let the Panel Do the Percentages
Discounts, VAT, commission and profit margin — define them once in Fenikya and they apply automatically to every order. Start selling with your own commission-free store.
Start 14 Days Free