Calculate percentage of marks, increase, decrease and more.
Four common percentage calculations in one tool. Switch between tabs.
Percentage
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Our Percentage Calculator bundles the four most common percentage calculations into a single tool. Switch between tabs to compute marks percentage, "X percent of Y", percentage increase or decrease, and "X is what percent of Y". Each calculation runs instantly as you type — no submit button required.
Percentages are deceptively simple, and even experienced students occasionally mix up the formulas. The most common mistake is dividing by the wrong base when computing percentage change. The rule: always divide by the original value, never the new value. A price rising from $40 to $50 is a 25% increase (10 ÷ 40), but a price falling from $50 to $40 is a 20% decrease (10 ÷ 50) — the absolute change is the same, but the base differs.
Percentage = ( Marks Obtained ÷ Total Marks ) × 100
Result = ( X × Y ) ÷ 100
Change % = ( ( New − Original ) ÷ |Original| ) × 100
Percentage = ( X ÷ Y ) × 100
Marks: You scored 178 out of 200 on an exam. Percentage = (178 ÷ 200) × 100 = 89%.
X% of Y: What is 15% of 250? (15 × 250) ÷ 100 = 37.5.
Percentage change: Your GPA went from 3.2 to 3.6. Change = ((3.6 − 3.2) ÷ 3.2) × 100 = (0.4 ÷ 3.2) × 100 = +12.5%.
X is what % of Y: 30 is what percent of 200? (30 ÷ 200) × 100 = 15%.
Percentages are the universal language of academic assessment. They let you compare performance across courses with different maximum scores (a 45/50 is not directly comparable to a 90/100, but both are 90%). They let you track improvement over time. And they form the basis for converting between percentage, GPA, and letter grade systems — a conversion our other calculators handle automatically.
Percentages also appear in scholarship eligibility ("top 10% of class"), attendance requirements ("minimum 75% attendance"), and admissions cutoffs ("minimum 60% in higher secondary"). Understanding how to compute and interpret percentages quickly is therefore a foundational academic skill that pays dividends throughout your education and career.
Divide the marks you obtained by the maximum possible marks, then multiply by 100. For example, if you scored 85 out of 100: (85 ÷ 100) × 100 = 85%.
Subtract the original value from the new value, divide by the original value, then multiply by 100. Example: a price rises from \$40 to \$50. Increase = (50 - 40) ÷ 40 × 100 = 25%.
Same formula as increase: (Original - New) ÷ Original × 100. Example: a price drops from \$50 to \$40. Decrease = (50 - 40) ÷ 50 × 100 = 20%.
Multiply Y by X and divide by 100. Example: 15% of 200 = (15 × 200) ÷ 100 = 30. This is the most common percentage calculation.
Divide the numerator by the denominator and multiply by 100. Example: 3/4 = 0.75 × 100 = 75%.
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