Percentage Calculator

What your result means

The Calculate menu has three options. Each one answers a different question, so pick the one that matches what you want to know.

Results show up to 4 decimal places, with extra zeros dropped and Indian digit grouping, so 1 out of 3 shows as 33.3333% and 1.5 lakh shows as 1,50,000. The Working row under the result shows the exact sum, so you can copy it into a notebook or check it by hand. In the change option, an Increase or Decrease label tells you the direction.

How percentages are calculated

“Percent” means “out of 100”. So 20% is 20 out of every 100, or 20 ÷ 100 = 0.2. Each option uses one simple formula.

• What is X% of Y: result = X ÷ 100 × Y. X is the percentage and Y is the number you take it from.
• X is what percent of Y: result = X ÷ Y × 100. X is the part and Y is the total.
• Percentage change: result = (Y − X) ÷ X × 100. X is the old value and Y is the new value. A positive answer is an increase and a negative one is a decrease. If X is negative, the calculator divides by its size without the minus sign, so the direction still reads correctly.

The change is always divided by the starting value. That is why going from 100 to 150 is a 50% increase, but going back from 150 to 100 is only a 33.3333% decrease.

How to use the percentage calculator

1. Choose an option from the Calculate menu.
2. Fill in the two boxes. Their labels change with the option: Percentage (X) and Of the number (Y), Value (X) and Total (Y), or From (X) and To (Y).
3. Read the result and the working. The calculator opens with 20% of 1,500, so you see an answer straight away, and it updates as you type.

Decimals and negative numbers are allowed. If the total or the starting value is 0, you see a message instead of a result, because you can’t divide by zero.

Worked examples

1. What is 20% of 1,500? 20 ÷ 100 × 1,500 = 0.2 × 1,500 = 300.
2. 437 is what percent of 500? Riya scored 437 marks out of 500. 437 ÷ 500 × 100 = 0.874 × 100 = 87.4%.
3. Change from ₹25,000 to ₹28,500: Arjun’s salary went up. (28,500 − 25,000) ÷ 25,000 × 100 = 3,500 ÷ 25,000 × 100 = 14% increase.
4. Change from 1,200 to 900: a shop’s monthly orders fell. (900 − 1,200) ÷ 1,200 × 100 = −300 ÷ 1,200 × 100 = 25% decrease.

Percentage of marks

To find your marks percentage, choose “X is what percent of Y?”. Enter the marks you got as X and the maximum marks as Y.

Marks % = marks obtained ÷ total marks × 100

Add up the marks of all subjects first, then divide by the total of all maximum marks. For five subjects of 100 marks each, the total is 500. Do not average the subject percentages if the papers carry different maximum marks, because that gives a different answer. If your board or university counts only the best five subjects, or leaves out some papers, follow its rule.

The same option gives attendance. Present on 68 of 85 working days is 68 ÷ 85 × 100 = 80%. Our date calculator counts the working days for you. If your marksheet shows a CGPA instead of marks, use our CGPA to percentage converter.

Common percentages as fractions and decimals

Knowing a few of these by heart makes mental sums quick.

Discounts, reverse percentages and percentage points

Discounts

Choose “What is X% of Y?” with the discount as X and the price as Y. A shirt priced at ₹2,000 with 30% off has a discount of 30 ÷ 100 × 2,000 = ₹600, so you pay ₹2,000 − ₹600 = ₹1,400. A quicker way is to take 70% of ₹2,000, which is what you actually pay.

Reversing a percentage

To find the original number before a percentage was added, divide by (100 + rate) and multiply by 100. A bill of ₹1,180 that includes 18% GST had a price of 1,180 × 100 ÷ 118 = ₹1,000 before tax. Taking 18% off ₹1,180 gives ₹967.60, which is wrong, because the 18% was worked out on ₹1,000. For tax bills, our GST calculator does this in one step.

Percent vs percentage points

When a rate itself changes, there are two ways to describe it. If a loan rate goes from 8% to 9%, it rose by 1 percentage point, which is the simple difference. It also rose by 12.5 percent, because (9 − 8) ÷ 8 × 100 = 12.5. News reports and bank letters usually mean percentage points when they say a rate went up “by 1%”. To see what a rate change does to a loan, try our EMI calculator.

Percentage change vs percentage difference

Percentage change has a clear “before” and “after”, and you divide by the “before” value. Percentage difference compares two numbers with no order, such as the prices of two phones, and a common method divides the gap by the average of the two. This calculator gives percentage change only.

Limitations

• Zero as the base: “X is what percent of 0” and a change from 0 have no answer, so the calculator shows a message instead.
• Rounding: results stop at 4 decimal places. If you round a percentage and then use it in another sum, small differences can add up.
• Your rules first: exam boards, banks and tax rules sometimes round in their own way, such as to the nearest whole number or always upwards. Use their figure when it differs.

Key facts

• A percentage is a value in hundredths of a quantity, so 100% is the whole amount and 200% is twice it. (Britannica (opens in new tab))
• The word “percent” comes from the Latin word centum, meaning “hundred”, and the whole is always 100%. (Britannica (opens in new tab))
• In Excel, a percentage of a total is found by dividing the part by the total, then applying the Percentage format. (Microsoft Support (opens in new tab))
• Excel calculates percentage change with =(new − old) ÷ old, written as =(C2-B2)/B2. (Microsoft Support (opens in new tab))
• To raise an amount by a percentage in Excel, multiply by 1 plus the rate, as in =B2*(1+C2). (Microsoft Support (opens in new tab))