Pick what you want: a percent of a number, what percent, increase or decrease, a price after discount, or the percentage of your marks. For example, 15% of 2,000 is 300, and 935 out of 1,100 is 85%.
Enter the two numbers. Bangla or English digits both work.
Open “How it was calculated” to see the steps.
Five percentage formulas
What you want
Formula
Example
Percent of a number
number × rate ÷ 100
15% of 2,000 = 300
What percent
part ÷ total × 100
450 of 600 = 75%
Increase / decrease
(new − old) ÷ old × 100
800 → 1,000 = 25% increase
Marks percentage
obtained ÷ total × 100
935 of 1,100 = 85%
Price after discount
price − price × discount ÷ 100
20% off 2,500 = 2,000
Examples
Salary rise: from 25,000 to 28,000 taka = (28,000 − 25,000) ÷ 25,000 × 100 = 12%.
SSC marks: 1,092 out of 1,300 = 1,092 ÷ 1,300 × 100 = 84%.
Things to watch
Know the base: 100 minus 20% is 80, but 80 plus 20% is 96, not 100, because the base differs.
Successive discounts don’t add up: 20% off and then another 10% off is 28% in total, not 30%.
Percentage points vs percent: an interest rate going from 8% to 10% rises by 2 percentage points, which is a 25% increase.
More: using the % key on a basic calculator
The % key: on most basic calculators, 2000 × 15 % shows 300 directly, and 2500 − 20 % often shows the discounted price 2000. Behaviour differs between models, so the formula is the safer way.
Fraction to percent: multiply by 100, e.g. 3/4 = 0.75 = 75%.
Percent to decimal: divide by 100, e.g. 12.5% = 0.125.
Frequently asked questions
What is the percentage formula?
Percentage = (part ÷ total) × 100. For example, 450 out of 600 is (450 ÷ 600) × 100 = 75%. To find a percent of a number: number × rate ÷ 100.
How do I find the percentage of my exam marks?
Divide the marks obtained by the full marks and multiply by 100. For example, 935 out of 1,100 is (935 ÷ 1,100) × 100 = 85%.
How do I calculate a percentage increase or decrease?
(new − old) ÷ old × 100. A positive result is an increase, a negative one a decrease. From 800 to 1,000 is a 25% increase; from 1,000 to 800 is a 20% decrease.
How do I find the price after a discount?
Discount = price × rate ÷ 100; new price = price − discount. A 20% discount on 2,500 taka saves 500, so the price becomes 2,000.
How much zakat is due as a percentage?
2.5% of zakatable wealth. Choose “Percent of a number”, enter 2.5 and the amount. See the zakat calculator for the full method.