％ Marks · Change · Reverse · Discount · Formula shown
Percentage Calculator
Every common percentage question in one page: X% of Y, X is what percent of Y, percentage increase or decrease, original value before a % change, discounts, successive percentages and a subject-wise marks percentage with best of 5. Answers update as you type and show the working.
1. What is X% of Y?
What is % of ?
2. X is what percent of Y?
is what % of ?
3. Percentage increase or decrease (from → to)
From to
4. Increase or decrease a number by a percentage (discount, hike, markup)
%
5. Reverse percentage — find the original value
After a % the value is
6. Successive percentages (e.g. 20% off + extra 10% off)
Use negative numbers for discounts or falls, positive for hikes or growth.
7. Marks percentage calculator (subject-wise)
Subject
Marks
Out of
%
CBSE uses 33%. Many universities use 35% or 40%.
CBSE-style: CGPA ≈ % ÷ 9.5
Division bands shown: Distinction ≥ 75%, First ≥ 60%, Second ≥ 50%, Third ≥ pass mark. Boards and universities differ (some use 45% for second class, or English-plus-best-four for ICSE), so check your official rules. For CGPA-based results use the CGPA to percentage calculator.
8. Percentage points vs percent change
From % to %
🔒Everything is calculated in your browser. Subject marks are kept only in this browser's local storage; nothing is uploaded.
Percentage formulas with examples
Question
Formula
Example
X% of Y
Y × X ÷ 100
18% of 2,500 = 450
X is what % of Y
X ÷ Y × 100
45 of 60 = 75%
% change
(New − Old) ÷ Old × 100
25,000 → 28,000 = +12%
Decrease by X% (discount)
Y × (100 − X) ÷ 100
₹1,999 at 40% off = ₹1,199.40
Original before X% increase
Final ÷ (1 + X ÷ 100)
1,180 after +18% → 1,000
Successive changes
(1 + a)(1 + b) − 1
−20% then −10% = −28%
Marks percentage
Total obtained ÷ total maximum × 100
432 / 500 = 86.4%
How to calculate percentage of marks for 5 or 6 subjects
Add the marks scored in every subject and add the maximum marks separately. For five subjects out of 100 each with 86, 91, 78, 95 and 82, the total is 432 out of 500, so the percentage is 432 ÷ 500 × 100 = 86.4%. Add a sixth subject of 88 and it becomes 520 ÷ 600 × 100 = 86.67%. Many admission forms for CBSE students ask for the best five subjects; set "Best of N" to 5 and the calculator picks the five highest-scoring subjects by percentage.
When papers have different maximum marks (say theory out of 70 and practical out of 30, or a subject out of 50), always add the actual marks and maximums. Averaging the subject percentages gives a different, usually wrong, figure when maximums differ — the calculator shows both so you can see the gap.
Common percentage mistakes
Reversing a percentage by subtracting it. A ₹1,180 price that includes 18% is not ₹1,180 − 18%; the original is 1,180 ÷ 1.18 = ₹1,000. For tax-specific cases use the GST calculator.
Adding successive discounts. "Flat 50% + extra 20% off" is 60% off, not 70%.
A rise and fall of the same % don't cancel. +10% then −10% leaves you 1% below where you started.
Mixing percent and percentage points. A cut-off moving from 40% to 50% is +10 points but +25% relative.
FAQ
How do I calculate a percentage?
Percentage = (part ÷ whole) × 100. Example: 45 out of 60 is 45 ÷ 60 × 100 = 75%. To find X% of a number, multiply the number by X and divide by 100: 18% of 2,500 = 2,500 × 18 ÷ 100 = 450.
How do I calculate percentage of marks?
Add the marks you scored in all subjects, add the maximum marks of all subjects, then divide and multiply by 100. Example: 86 + 91 + 78 + 95 + 82 = 432 out of 500, so 432 ÷ 500 × 100 = 86.4%. If subjects have different maximum marks, add the actual marks and maximums; do not average the subject percentages.
How do I calculate percentage increase or decrease?
Percentage change = (new value − old value) ÷ old value × 100. Example: a salary going from ₹25,000 to ₹28,000 is (28,000 − 25,000) ÷ 25,000 × 100 = 12% increase. A negative result is a decrease.
How do I find the original price before a percentage increase or discount?
Divide the final value by (1 + rate ÷ 100) for an increase or by (1 − rate ÷ 100) for a decrease. Example: a price of ₹1,180 after an 18% increase was originally 1,180 ÷ 1.18 = ₹1,000. Subtracting 18% of 1,180 gives the wrong answer.
Is 20% off plus an extra 10% off the same as 30% off?
No. Successive percentages multiply: 1 − (0.80 × 0.90) = 0.28, so 20% then 10% off is a 28% total discount, not 30%. The successive percentage section shows this for any two or three steps.
What is the difference between percentage points and percent?
A change from 40% to 50% is a rise of 10 percentage points but a 25% relative increase, because (50 − 40) ÷ 40 × 100 = 25%. News and exam cut-offs usually talk in percentage points.
Is my data uploaded anywhere?
No. Every calculation runs in your browser, and your subject marks are saved only in your own browser's local storage so they are still there when you come back.