About the Percentage Calculator
Percentages come up everywhere: exam marks, price changes, interest rates, statistics and growth figures. This percentage calculator handles the three questions people ask most often in one place.
Choose what you want to find, enter two numbers and get the answer instantly, rounded to a sensible number of decimal places.
How to use it
- Choose the type of calculation from the list.
- Enter Value A and Value B.
- Press Calculate.
- The answer appears below the button.
Formula
A% of B = A × B ÷ 100. A as a percent of B = A ÷ B × 100. Percent change = (B − A) ÷ A × 100.
Example
Your score went from 40 to 50 points. Percent change = (50 − 40) ÷ 40 × 100 = 25%, so it increased by 25%.
Common mistakes to avoid
A common mistake is mixing up a percentage increase with a percentage point change. If a rate goes from 4% to 5%, it has risen by 1 percentage point, but that is a 25% increase in the rate itself (1 divided by 4 is 25%).
Another mistake is dividing by the wrong number. To find what percent 30 is of 200, divide 30 by 200 and multiply by 100, which gives 15%. Dividing 200 by 30 gives a result that means nothing here.
Everyday examples
If a class has 40 students and 32 pass, the pass rate is 32 divided by 40, multiplied by 100, which is 80%. Percentages make results from classes of different sizes easy to compare, because every group is measured on the same scale of one hundred.
Percentages also help with budgets. If you spend 3,000 from a monthly income of 25,000, that is 12% of your income. Tracking this figure month by month shows whether spending is rising or falling, even when the rupee amounts look similar. A percentage shows the share of the whole, which is often more useful than the amount alone when you decide where to cut back.
Everyday uses
Percentages are behind exam results, salary hikes, price rises, interest rates and loan offers. If your salary goes from ₹40,000 to ₹46,000, the percent change option shows a 15% hike. If you scored 432 out of 500, the "A is what % of B" option shows 86.4%.
For price changes over several steps, work out each step separately. Two increases of 10% make 21% in total, not 20%, because the second increase is applied to the already higher amount.
Frequently asked questions
What is the difference between percent and percentage points?
Percentage points measure the gap between two percentages. A rate moving from 10% to 12% rose by 2 percentage points, which is a 20% increase in relative terms.
Why is a 50% drop not undone by a 50% rise?
Because the second percentage applies to a smaller number. 100 falls 50% to 50, and 50% of 50 is only 25, bringing it back to 75.
How do I turn marks into a percentage?
Choose "A is what % of B", enter your marks as A and the total marks as B.
Can I use negative numbers?
Yes. A negative percent change means a decrease.