Percentage Calculator
A percentage expresses a number as a fraction of 100. This calculator handles the three most common percentage questions in one place: finding a percentage of a number, working out what percent one number is of another, and calculating the percentage increase or decrease between two values.
How it works
Pick the type of calculation, enter your two numbers, and the result updates instantly along with a plain-English restatement so you can see exactly what was computed.
X% of Y = (X ÷ 100) × Y · X is (X ÷ Y × 100)% of Y · Change = (Y − X) ÷ X × 100Example. 25% of 200 is 50. Put another way, 50 is 25% of 200, and going from 200 to 250 is a 25% increase.
Finding what percentage one number is of another
This is the question people phrase most awkwardly - "what percent of what", "percentage of another number", "percent to number" - and they all mean the same calculation. Pick "X is what percent of Y", put the part in X and the whole in Y, and divide. 30 out of 120 is 25%, because 30 ÷ 120 = 0.25. The order matters: the number you are measuring goes first, the total goes second. Swap them and 120 becomes 400% of 30, which is a real answer to a different question.
Percentage increase vs decrease
A percentage change is always measured relative to the starting value. Going from 100 to 150 is a 50% increase, but going back from 150 to 100 is only a 33.3% decrease - because the base you divide by is different each time. That asymmetry trips a lot of people up.
Frequently asked questions
How do I calculate a discount?
Use 'What is X% of Y' with X as the discount percent and Y as the price to get the amount off, then subtract it from the price. For example, 20% of ₹2,000 is ₹400, so the discounted price is ₹1,600.
How do I calculate what percentage one number is of another?
Choose 'X is what percent of Y', enter the part as X and the total as Y, and divide the first by the second. 45 is 60% of 75, because 45 ÷ 75 = 0.6. If the answer comes out above 100%, the two numbers are the wrong way round.
How do I convert a percentage back into a number?
Use 'What is X% of Y' with X as the percentage and Y as the total. 15% of 480 is 72. This is the reverse of asking what percent one number is of another, and it is the mode you want when you already know the rate and need the amount.
How do I find the percentage difference between two numbers?
Use the '% change from X to Y' mode. It divides the difference by the starting value and multiplies by 100, telling you the increase or decrease as a percentage.
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