Percentage Calculator
Calculate percentages instantly - find X% of Y, percentage change, add or subtract percentages.
About the Percentage Calculator
Percentage calculations appear in almost every aspect of daily life - from GST and discounts to exam scores, interest rates, salary hikes, and investment returns. Despite being a core mathematical concept, many people make errors when dealing with percentages, especially with percentage change (which is not the same as percentage points). This calculator handles all common percentage problems instantly.
Core Percentage Formulas
% of X: (P/100) × X · X is what % of Y: (X/Y) × 100 · % change: ((New − Old)/Old) × 100
Percentage point change ≠ percentage change · E.g., 10% → 15% is a 5 percentage point increase, but a 50% relative increase
Worked Example
Salary hike from ₹8 lakh to ₹9.2 lakh per annum
Percentage increase = ((9.2 − 8) / 8) × 100 = 15% hike
Tips & Insights
- 1
A 20% discount followed by a 20% price increase does NOT bring you back to the original price (net: -4%).
- 2
When comparing interest rates vs inflation, use real return = ((1 + nominal) / (1 + inflation)) - 1.
- 3
GST is calculated on base price, not on the final price - use the extract-GST approach when working backwards from MRP.
- 4
Percentage change and absolute change tell different stories - a 10% raise on 5 lakh is very different from 10% on 50 lakh.
- 5
CAGR (Compound Annual Growth Rate) is a percentage that measures true annual growth rate for investments over time.
- 6
Percentage points and percentages are different: if a fund's return rises from 8% to 10%, that is a 2 percentage point increase but a 25% relative increase.
- 7
When splitting restaurant bills with GST, first remove the 5% or 18% GST to get the base amount, then split the base, not the gross total.
Why this matters for you
Misunderstanding percentages is one of the most common financial mistakes in daily life. Whether it is misreading a salary hike letter, overpaying on a flat 30% off sale, or comparing two loan offers by EMI without accounting for tenure, the root cause is almost always a percentage calculation error or a misinterpretation of what the percentage represents. Our calculator covers every standard percentage relationship so you can verify any claim in seconds.
Percentage change, in particular, trips people up in investing. A mutual fund that falls 30% then rises 30% is not back to where it started - it is actually down 9% from its original value. This is why equity investors who panic-sold during market crashes and bought back in after partial recovery still lost money even though the market appeared to have recovered. Understanding how losses and gains compound asymmetrically is the single most important percentage insight for retail investors.
For salary negotiations, tax planning, and everyday commerce in India, percentage fluency directly affects financial outcomes. GST calculation, TDS computation, incentive structures, and gratuity formulas all rely on accurate percentage arithmetic. A 1% error in a salary negotiation on a 20 lakh package is 20,000 rupees per year - compounding over a career. The calculator is a quick sanity check that costs nothing and prevents expensive errors.
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Frequently Asked Questions
How do I calculate X% of Y?+
Multiply Y by X and divide by 100. E.g., 25% of 200 = (25 x 200) / 100 = 50.
How do I find what percentage X is of Y?+
Divide X by Y and multiply by 100. E.g., 50 is what % of 200? = (50 / 200) x 100 = 25%.
How do I calculate percentage change?+
% Change = ((New - Old) / |Old|) x 100. A positive result is an increase, negative is a decrease. E.g., from 100 to 125 = +25%.
How do I add a percentage to a number?+
New value = Original x (1 + Rate/100). E.g., 200 + 10% = 200 x 1.10 = 220.
How do I calculate percentage increase or decrease?+
Percentage change = (New Value - Old Value) / Old Value x 100. If a stock goes from Rs. 200 to Rs. 250, the increase is (250-200)/200 x 100 = 25%. If it drops from Rs. 250 to Rs. 200, the decrease is (200-250)/250 x 100 = -20%. Note that a 25% gain followed by a 25% loss does not return to the original value - you end up at 93.75 (asymmetry of percentages). Always compute from the original base.
How do I calculate the original price after a discount?+
If a product is sold for Rs. 680 after a 15% discount, the original price = Sale Price / (1 - Discount%/100) = 680 / 0.85 = Rs. 800. This reverse calculation is essential when comparing discounted prices across stores: always back-calculate the original MRP to verify the discount is applied on the same base. Many retailers inflate MRP before applying a discount, making a 30% off offer actually equivalent to 10% off the competitive market price.
What is the difference between percentage point change and percentage change?+
A percentage point change is the arithmetic difference between two percentages. A percentage change is the relative change expressed as a percentage of the original value. Example: a mutual fund's 3-year return improves from 8% to 12%. Percentage point change: 12 - 8 = 4 percentage points. Percentage change in the return rate: (12 - 8) / 8 x 100 = 50%. Both statements are technically accurate but tell different stories. Financial media routinely conflate these - always clarify which measure is being cited, especially for interest rate changes, inflation reports, and return comparisons.