Percentage Calculator

FinanceLast updated: August 17, 2026

A percentage is a ratio that tells you how many of a whole's 100 equal parts you are taking, and it is everywhere in daily life: discount tags, interest rates, exam success rates, pay rises, and statistical tables are all expressed as percentages.

This calculator brings the three basic percentage operations together on one screen: finding a given percentage of a number (what is 18% of 250?), working out what percentage one number is of another (30 is what percent of 120?), and measuring the percentage change between two values (what is the percentage increase from 80 to 100?). Pick the direction, enter the values, and read the result instantly.

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Percentage Rates Used Most Often in Daily Life

Percentages come up most often in tax, deduction, and price calculations. The rates below are the ones commonly encountered in Turkey; you can use them as a reference when deciding which rate to enter.

VAT rates
1% · 10% · 20%
Respectively basic foodstuffs, the reduced rate (food, books, health, accommodation), and the standard rate
Income tax brackets
15% – 40%
The progressive brackets applied to employment income: 15%, 20%, 27%, 35%, and 40%
Employee social security deduction
15%
A 14% social security premium and a 1% unemployment insurance employee share, both taken from the gross wage
Stamp duty
7.59 per thousand
Applied to the gross amount on the payroll; as a percentage it is 0.759%
Withholding tax on commercial rent
20%
On a property rented as business premises, the tenant withholds income tax at this rate from the gross rent

Rates currently in force; tax rates can change during the yearKaynak: Legislation of the Turkish Revenue Administration and the Social Security Institution

Formula

p% of A = A × p / 100
A as a percentage of B = (A / B) × 100
Percentage change = ((New − Old) / Old) × 100

In a percentage change the denominator is always the OLD value. Going from 80 to 100 is a 25% increase, while going from 100 to 80 is a 20% decrease — the two directions do not give the same percentage.

How to Calculate

  1. Choose the calculation type: percentage of a number, share of a whole, or percentage change.
  2. Fill in the fields that appear for the type you picked (decimal points and decimal commas are both accepted).
  3. Read the calculated percentage and the supporting values in the results section.
  4. Check the result against the plain-language explanation on the interpretation line.

Worked Examples

A percentage of a number

Multiplying 250 by 18 and dividing by 100 gives 45, which is 18% of 250. Added on top it makes 295; taken off it makes 205. This is the core operation behind VAT and tip calculations.

18% of 250: 45 · Number + percentage (after the increase): 295 · Number − percentage (after the discount): 205

A is what percent of B?

What percent of 120 is 30? The ratio is 0.2500 as a decimal and 25.00% as a percentage. On a 120-question exam, for example, 30 correct answers cover 25% of the questions.

30 as a percentage of 120: 25.00% · Ratio (decimal): 0.2500

Percentage change (an increase)

If the price of an item rises from 80 to 100, the change is ((100 − 80) / 80) × 100 = +25%. Had the same price fallen from 100 to 80, the change would be −20%.

Percentage change: +25.00% · Absolute difference: 20 · Old value: 80

Frequently Asked Questions

How do you calculate a percentage of a number?
Multiply the number by the percentage rate and divide by 100. For 18% of 250, for example, you compute 250 × 18 / 100 = 45. A quicker route is to convert the rate to a decimal and multiply (250 × 0.18 = 45).
How do you find what percentage one number is of another?
Divide the part by the whole and multiply by 100: (A / B) × 100. For instance, 30 is (30 / 120) × 100 = 25% of 120. The thing to watch is which of the two numbers is the whole (the denominator).
Why are percentage increases and decreases not symmetric?
Because the denominator changes. Going from 80 to 100 is a 25% increase relative to the old value of 80; going from 100 to 80 is a 20% decrease relative to the old value of 100. That is why a price that rose by 25% has to fall by 20%, not 25%, to return to where it started.
Are percentage points and percentage change the same thing?
No. If an interest rate rises from 40% to 50% it has increased by 10 percentage points; the percentage change, however, is (50 − 40) / 40 = 25%. The two are frequently confused in the news: points describe the absolute difference, percentage change the relative one.
Can percentage change be calculated with negative numbers?
It can, but it needs care. This calculator uses the absolute value of the old value in the denominator, so a move from −50 to −25 is reported as +50% (an improvement). If the old value is 0, the percentage change is undefined.
Can I enter a percentage rate with decimals?
Yes. Rates such as 12.5% can be entered with either a decimal point (12.5) or a decimal comma (12,5). The calculator recognizes both notations and formats the results for the language you are reading in.