How do I calculate the percentage of marks?

Divide your obtained marks by the total marks and multiply by 100. Example: 450 out of 600 = (450 ÷ 600) × 100 = 75%. Use the 'What percent is X of Y' mode here and enter obtained marks and total marks.

How do I calculate a percentage increase?

Percentage increase = ((New Value − Old Value) ÷ Old Value) × 100. Example: price increased from ₹500 to ₹650 = ((650−500) ÷ 500) × 100 = 30% increase.

What is reverse percentage?

Reverse percentage finds the original value before a percentage was applied. If a price after 20% increase is ₹1,200, the original is ₹1,200 ÷ 1.20 = ₹1,000. Useful for finding pre-tax or pre-discount amounts.

How do I find what percent one number is of another?

Divide the part by the whole and multiply by 100. Example: 45 is what percent of 180? (45 ÷ 180) × 100 = 25%.

What is the difference between percentage change and percentage difference?

Percentage change compares a new value to a specific old value (directional). Percentage difference compares two values without a direction — it is the absolute difference divided by the average of the two values, multiplied by 100.

Percentage Calculator – Find X% of Y, Increase, Decrease & Reverse

Solve any percentage problem instantly. Find what X% of Y is, calculate percentage increase or decrease between two numbers, work out what percentage one number is of another, find the reverse percentage, or compare two values by their percentage difference. All modes in one calculator, free and instant.

Percentage Calculator

What is X% of Y?

What is% of?

Percentage Calculator in Common Phrases

Quick formulas for everyday percentage questions

What is% of?

is what % of?

is% of what?

Percentage Increase Calculator

Increase a value by a given percentage

Increaseby%

Percentage Decrease Calculator

Decrease a value by a given percentage

Decreaseby%

Percentage Difference Calculator

Find the percentage difference between two values

Value 1Value 2

Percentage Change Calculator

Find the percentage increase or decrease between two values

From→ To

Reverse Percentage Calculator

Find the original value before a percentage was applied

Final value isafter a%

Percentage Formulas

X% of Y

(X ÷ 100) × Y

e.g. 25% of 200 = 50

X is what % of Y

(X ÷ Y) × 100

e.g. 50 is 25% of 200

Percentage increase

Value × (1 + X ÷ 100)

e.g. 200 + 15% = 230

Percentage decrease

Value × (1 − X ÷ 100)

e.g. 200 − 15% = 170

Percentage difference

|V1 − V2| ÷ ((|V1| + |V2|) ÷ 2) × 100

e.g. Diff between 10 & 6 = 50%

Percentage change

(New − Old) ÷ |Old| × 100

e.g. From 50 to 75 = 50% increase

Reverse percentage

Final ÷ (1 ± X ÷ 100)

e.g. $120 after 20% increase → $100

Common Percentage Calculations

Calculating marks percentage

Divide your total marks by the maximum marks and multiply by 100. Or use the 'X is what % of Y' mode to get the result directly.

Discount and sale prices

Find the exact price after a 20%, 30%, or custom discount by entering the original price and the percentage off.

Tracking percentage change

Calculate revenue growth, score improvement, or price changes by entering the old and new values in the percentage change mode.

How to Use the Percentage Calculator

Choose calculation type

Select from: X% of Y, percent increase/decrease, what percent is X of Y, or reverse percentage.

Enter values

Provide the numbers for your chosen calculation type.

Get result instantly

The result updates as you type with no button needed.

Copy or use

Copy the result or read the working shown below the answer.

Understanding Percentage Increase vs. Decrease

Percentage increase and decrease are both forms of percentage change — the direction depends on whether the new value is higher or lower than the original. The formula is the same: ((New − Old) ÷ Old) × 100. If the result is positive, it is an increase; if negative, it is a decrease. Common uses include calculating salary hikes (base salary increased from ₹40,000 to ₹46,000 = 15% increase), tracking price changes (petrol price rose from ₹95 to ₹102 = 7.37% increase), and measuring score improvement (marks improved from 68% to 78% = 14.7% increase). Note that a 50% decrease followed by a 50% increase does not return to the original — a value of 100 halved to 50 and then increased by 50% becomes 75, not 100. This asymmetry matters in financial and investment contexts.

How to Calculate Percentage of Marks for Exams

To calculate your exam percentage, divide total marks obtained by the maximum possible marks, then multiply by 100. If you scored 418 out of 500, your percentage is (418 ÷ 500) × 100 = 83.6%. For competitive exams with multiple subjects, calculate the aggregate by summing all obtained marks and dividing by the total maximum marks across subjects. Some exams use normalized scoring or percentile ranks instead of raw percentages — those are different concepts. This calculator handles the standard marks-to-percentage conversion. Use the “What percent is X of Y” mode and enter your marks as X and maximum marks as Y to get the result in one step.

Frequently Asked Questions

How do I calculate the percentage of marks?: Divide your obtained marks by the total marks and multiply by 100. Example: 450 out of 600 = (450 ÷ 600) × 100 = 75%. Use the 'What percent is X of Y' mode here and enter obtained marks and total marks.
How do I calculate a percentage increase?: Percentage increase = ((New Value − Old Value) ÷ Old Value) × 100. Example: price increased from ₹500 to ₹650 = ((650−500) ÷ 500) × 100 = 30% increase.
What is reverse percentage?: Reverse percentage finds the original value before a percentage was applied. If a price after 20% increase is ₹1,200, the original is ₹1,200 ÷ 1.20 = ₹1,000. Useful for finding pre-tax or pre-discount amounts.
How do I find what percent one number is of another?: Divide the part by the whole and multiply by 100. Example: 45 is what percent of 180? (45 ÷ 180) × 100 = 25%.
What is the difference between percentage change and percentage difference?: Percentage change compares a new value to a specific old value (directional). Percentage difference compares two values without a direction — it is the absolute difference divided by the average of the two values, multiplied by 100.

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