Free Percentage Calculator — 10 Calculators: GST, Discount, Tip, Marks & More (2026)

Ten percentage calculators on one page, each with the formula shown. Calculate what % of a number is, find percentage change, apply discounts, calculate GST (India's 5/12/18/28% slabs), split restaurant tips, find profit/loss %, check exam marks, and more — all updating in real time as you type.

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What is X% of Y?

Most common — find a percentage of any number

% of

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X is what % of Y?

Find what percentage one number is of another

is what % of

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Percentage Change

Calculate % increase or decrease between two values

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Increase / Decrease by %

Apply a percentage increase or decrease to any value

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Discount Calculator

Find final price and savings after a discount

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% off

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Tip Calculator

Split restaurant bill with tip across people

Bill ₹Tip%

Split betweenpeople

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GST Calculator — India

All 5 GST slabs — add or extract tax from any amount

₹

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Marks / Grade Percentage

Calculate your exam percentage and grade (CBSE/ICSE/State)

out of

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Profit & Loss %

Calculate profit or loss percentage from cost and selling price

Cost ₹

Sell ₹

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Percentage Difference

Compare two values symmetrically — no fixed reference point

Unlike % change, this is symmetric — A vs B gives the same result as B vs A.

10 Calculators in One

What is X% of Y · X is what % of Y · Percentage Change · Increase/Decrease by % · Discount · Tip · GST (India) · Marks/Grade % · Profit & Loss · Percentage Difference. All on one page.

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GST Calculator for India

All 5 GST slabs — 0%, 5%, 12%, 18%, 28%. Add GST to a base price, or extract GST from an MRP that includes tax. Shows base amount, tax amount, and total in one click.

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Discount & Tip Calculator

Enter original price and discount % to see final price plus exact savings. Tip calculator splits restaurant bills across any number of people with quick 5/10/15/18/20% tip buttons.

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Marks & Grade % (CBSE/ICSE)

Enter marks obtained and total marks for an instant percentage plus grade classification — O (Outstanding), A+, A, B, C, Pass, Fail — matching standard Indian board grading conventions.

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Instant — No Button Needed

All 10 calculators update in real time as you type. Every result shows the formula used so you understand the math, not just the answer. Copy any result with one click.

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Calculation History

Every result you copy is automatically saved to history (up to 30 entries). Refer back to previous calculations without re-entering numbers. Stored in your browser — no account needed.

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How Percentage Calculations Work — The Core Formulas

Every percentage problem is a variation of one equation: Part = (Percentage ÷ 100) × Whole. Rearranging this gives the other two formulas:

Question	Formula	Example	Answer
What is 15% of 200?	(15 ÷ 100) × 200	0.15 × 200	30
30 is what % of 200?	(30 ÷ 200) × 100	0.15 × 100	15%
30 is 15% of what?	30 ÷ (15 ÷ 100)	30 ÷ 0.15	200
200 to 240 — % change?	((240−200) ÷ 200) × 100	(40 ÷ 200) × 100	20% ▲
Add 18% GST to ₹1,000	1,000 × (1 + 18/100)	1,000 × 1.18	₹1,180
₹1,180 incl. 18% GST?	1,180 ÷ 1.18	Base = ₹1,000	GST = ₹180

The shortcut for mental math

For any percentage: move the decimal two places left and multiply. 15% of 240 = 0.15 × 240. Easier trick: 15% = 10% + 5%. 10% of 240 = 24. Half of 24 = 12. So 15% = 24 + 12 = 36. For 1%: just move the decimal two places left. 1% of 2,400 = 24. Then multiply by the percentage.

GST in India — Four Slabs, How to Calculate, and Common Mistakes

India unified its indirect tax system under GST in July 2017, replacing VAT, service tax, excise duty, and several other levies. GST has five rates, and knowing which applies to what you are buying or selling can save or cost you significantly.

GST Rate	Category	Common Examples
0%	Exempt	Fresh vegetables, rice, wheat, eggs, milk, books, newspapers, salt, contraceptives
5%	Essential	Packaged food, economy hotels (<₹1,000/night), transport, small restaurants
12%	Standard I	Computers, butter, cheese, processed food, umbrellas, mobile phones
18%	Standard II	Most services, A/C restaurants, financial services, electronics, soaps, hair oil
28%	Luxury	Cars (+ additional cess), tobacco, aerated drinks, cement, luxury items

Adding GST (Exclusive)

When a vendor quotes a price excluding GST:

Total = Base × (1 + GST%/100)
₹10,000 + 18% = ₹10,000 × 1.18 = ₹11,800

Extracting GST (Inclusive)

When an MRP already includes GST:

Base = Total ÷ (1 + GST%/100)
₹11,800 ÷ 1.18 = ₹10,000 base + ₹1,800 GST

Where You Use Percentages Every Day in India

Percentages appear in nearly every financial decision. Here are the most common scenarios in Indian daily life, with the exact formula for each:

Salary Hike

New Salary = Current × (1 + Hike%/100). The average increment in Indian IT was 8–10% in FY2024–25. A ₹12 LPA package with a 15% hike becomes ₹12L × 1.15 = ₹13.8 LPA. Counter-offer rule: to match a competitor offer, calculate: needed hike = ((Offer − Current) ÷ Current) × 100.

EMI Down Payment

Banks require 10–25% of the vehicle or property value as down payment. For a ₹15 lakh car with 20% down: ₹15L × 20% = ₹3L down payment, ₹12L financed. For home loans: RBI mandates 10–25% LTV margin depending on loan amount. For loans above ₹75L, you must fund at least 25% yourself.

Shopping Discounts

During Amazon Great Indian Festival or Flipkart Big Billion Days, discounts of 30–80% are common. Always verify: Discount % = ((MRP − Sale Price) ÷ MRP) × 100. If a ₹5,000 item is on sale for ₹3,750, that is 25% off. Watch for misleading MRPs — compare the sale price against other stores' regular prices.

Board Exam Marks (CBSE/ICSE)

CBSE Class 10 and 12 use percentage = (Total Obtained ÷ Total Max) × 100. For CGPA conversion: multiply CGPA × 9.5 to get approximate percentage. Most engineering colleges require 75%+ aggregate in 12th PCM for direct admission. Top NITs typically ask for 75% or top 20 percentile in state board.

Inflation & Price Rise

India's CPI inflation averaged around 5.5% in FY2024–25. If your grocery basket cost ₹8,000/month and inflation is 6%, next year it costs ₹8,000 × 1.06 = ₹8,480. Over 5 years at 6%: ₹8,000 × (1.06)⁵ = ₹10,705 — a 33.8% real increase. Understanding compound inflation helps set savings and investment targets.

FD and Savings Returns

FD rates in India range 6.5–8.5% for 1–3 year tenures (as of early 2026). A ₹1 lakh FD at 7.5% for 1 year returns ₹1,07,500 (simple) or ₹1,07,763 (quarterly compound). The difference: simple interest = principal × rate × time, compound interest = principal × (1 + r/n)^(n×t). Always compare using effective annual yield, not nominal rate.

Common Percentage Mistakes and How to Avoid Them

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Adding percentages directly

If a price increases 20% then decreases 20%, most people assume you are back to the original. You are not. Starting at ₹100: +20% → ₹120. −20% of ₹120 → ₹96. The final value is 96% of the original — a 4% net decrease. Always apply percentages sequentially, not additively.

✓ Fix: Use (1 + r₁/100) × (1 + r₂/100) for compound effects

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Calculating % change the wrong way

A shop says 'price reduced by ₹300 from ₹2,500'. The discount percentage is (300 ÷ 2,500) × 100 = 12%, not (300 ÷ 2,200) × 100 = 13.6%. The denominator must be the original (old) value, not the new one. This mistake makes discounts look larger than they are.

✓ Fix: Always divide by the original (starting) value, not the final value

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Confusing % change with % difference

The percentage change from A to B is different from the percentage difference between A and B. Change is directional (A→B ≠ B→A). Difference is symmetric. From 80 to 100: change = 25%. From 100 to 80: change = −20%. Difference between 80 and 100 = |80−100| ÷ 90 × 100 = 22.2% (same either way).

✓ Fix: Use % change for before/after. Use % difference for comparing two equal measures.

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Confusing GST-inclusive and GST-exclusive prices

A freelancer charges ₹50,000 for a project. Client says they will add 18% GST on top: total = ₹59,000. But if the ₹50,000 was already GST-inclusive, the base amount is ₹50,000 ÷ 1.18 = ₹42,372 and GST is ₹7,628. The freelancer's taxable income differs by ₹7,628 depending on the interpretation.

✓ Fix: Always confirm whether a quoted price is before or after GST

Frequently Asked Questions

What is the basic formula to calculate percentage?▼

The fundamental percentage formula is: Percentage = (Part ÷ Whole) × 100. For example, if you scored 45 marks out of 60, your percentage is (45 ÷ 60) × 100 = 75%. To reverse this and find the part from a known percentage: Part = (Percentage ÷ 100) × Whole. So 15% of 200 = (15 ÷ 100) × 200 = 30. These two formulas cover the vast majority of everyday percentage calculations.

How do I calculate percentage increase or decrease?▼

Percentage change = ((New Value − Old Value) ÷ |Old Value|) × 100. If the result is positive, it is an increase; if negative, it is a decrease. Example: A product price goes from ₹800 to ₹960. Change = ((960 − 800) ÷ 800) × 100 = 20% increase. Example: Your electricity bill goes from ₹3,200 to ₹2,720. Change = ((2,720 − 3,200) ÷ 3,200) × 100 = −15% (a 15% decrease). Note: Use the absolute value of the old value in the denominator so that decreases from a negative starting point are handled correctly.

How is GST calculated in India?▼

India has five GST slabs: 0%, 5%, 12%, 18%, and 28%. There are two scenarios: (1) Exclusive GST (adding GST to a base price): Final Amount = Base Amount × (1 + GST Rate/100). Example: ₹10,000 + 18% GST = ₹10,000 × 1.18 = ₹11,800. GST amount = ₹1,800. (2) Inclusive GST (extracting GST from an MRP that already includes tax): Base Amount = Total ÷ (1 + GST Rate/100). Example: ₹11,800 inclusive of 18% GST → Base = ₹11,800 ÷ 1.18 = ₹10,000. GST = ₹11,800 − ₹10,000 = ₹1,800. GST is further split into CGST + SGST (for intra-state) or IGST (for inter-state) — each being half the total rate for CGST/SGST.

What is the difference between percentage change and percentage difference?▼

Percentage change is directional — it compares a new value to an old value, and the order matters. Formula: ((New − Old) ÷ |Old|) × 100. If you go from 100 to 150, that is a 50% increase. If you go from 150 to 100, that is a −33.3% decrease. Percentage difference is symmetric — it treats both values equally and does not imply one is the reference. Formula: |A − B| ÷ ((A + B) ÷ 2) × 100. Comparing 100 and 150 gives the same percentage difference as comparing 150 and 100 (40%). Use percentage change when you have a clear before/after. Use percentage difference when comparing two independent measurements.

How do I add or subtract a percentage from a number?▼

To increase a number by X%: Result = Number × (1 + X/100). Example: Increase ₹5,000 by 12% → ₹5,000 × 1.12 = ₹5,600. To decrease a number by X%: Result = Number × (1 − X/100). Example: Decrease ₹5,000 by 12% → ₹5,000 × 0.88 = ₹4,400. A common mistake is doing ₹5,000 + 12 or ₹5,000 × 12 — remember to divide by 100 first. These formulas are used for salary hikes, discounts, inflation adjustments, EMI calculations, and any percentage-based change.

How is discount percentage calculated for online shopping?▼

Discount Percentage = ((MRP − Sale Price) ÷ MRP) × 100. Example: A phone has an MRP of ₹25,000 and is on sale for ₹19,500. Discount = ((25,000 − 19,500) ÷ 25,000) × 100 = 22% off. Savings = ₹5,500. To find the final price from a known discount: Final Price = MRP × (1 − Discount%/100). Example: ₹25,000 with 22% off → ₹25,000 × 0.78 = ₹19,500. Always verify: the 'discount' shown in e-commerce may be calculated on a fictitious MRP that is inflated to make the deal look better than it is.

How do I calculate profit and loss percentage?▼

Profit Percentage = ((Selling Price − Cost Price) ÷ Cost Price) × 100 when Selling Price > Cost Price. Loss Percentage = ((Cost Price − Selling Price) ÷ Cost Price) × 100 when Selling Price < Cost Price. Example: You buy a laptop for ₹48,000 and sell it for ₹55,200. Profit = ₹7,200. Profit % = (7,200 ÷ 48,000) × 100 = 15%. Note: Both profit % and loss % are always calculated on the Cost Price (not the selling price), unless specified otherwise. In some business contexts (like retail margin), the calculation is done on selling price — this is called gross margin percentage.

How to calculate marks percentage for CBSE or board exams?▼

Marks Percentage = (Total Marks Obtained ÷ Total Maximum Marks) × 100. For CBSE Class 12: if you scored 435 out of 500, your percentage is (435 ÷ 500) × 100 = 87%. For multiple subjects: add all subject marks and divide by the sum of maximum marks. CBSE uses letter grades mapped to grade points (CGPA system) alongside percentages: A1 (91–100), A2 (81–90), B1 (71–80), B2 (61–70), C1 (51–60), C2 (41–50), D (33–40). To convert CGPA to approximate percentage, multiply CGPA by 9.5 (CBSE formula).

What is percentage points, and how is it different from percentage?▼

Percentage points measure the arithmetic difference between two percentages. If interest rates rise from 6% to 8%, that is a 2 percentage point increase — but it is a 33.3% relative increase ((8−6)/6 × 100). This distinction matters in finance, economics, and reporting. When the RBI raises the repo rate from 6.5% to 6.75%, news reports say it increased by 25 basis points (0.25 percentage points) — not 3.8%. Politicians and advertisers sometimes exploit this ambiguity: 'our customer satisfaction improved by 50%' could mean it went from 80% to 82.5% (percentage change) or from 60% to 90% (percentage points). Always clarify which is meant.

How do I calculate a salary hike percentage?▼

Salary hike percentage = ((New Salary − Old Salary) ÷ Old Salary) × 100. Example: Current CTC is ₹8,40,000 per year. New offer is ₹10,08,000. Hike = ((10,08,000 − 8,40,000) ÷ 8,40,000) × 100 = 20%. To find what your new salary would be after a known hike: New Salary = Old Salary × (1 + Hike%/100). Example: ₹8,40,000 with a 15% hike → ₹8,40,000 × 1.15 = ₹9,66,000. The average salary increment in India's IT sector was 8–10% in 2024–25, while senior and specialist roles saw 15–25% increases driven by demand for AI and cloud skills.

Why do percentages of percentages not add up the way I expect?▼

Because percentages are relative, not additive. If a price increases by 20% and then decreases by 20%, you do NOT end up at the original price. Starting at ₹100: after 20% increase → ₹120. After 20% decrease of ₹120 → ₹96. You end up with ₹96, not ₹100. This is because the second percentage is applied to a different base. The combined effect of two successive percentage changes (x% then y%) is: net change = x + y + (x×y)/100. In the example: 20 + (−20) + (20×(−20)/100) = 0 − 4 = −4%. ₹100 × (1 − 4/100) = ₹96. This compounding effect is why loan EMIs, investment returns, and inflation need compound calculations rather than simple addition.

How is tip calculated at restaurants in India, and should I tip on GST?▼

In India, a voluntary tip (gratuity) of 10–15% is customary at sit-down restaurants that don't add a mandatory service charge. Many restaurants add a 5–10% service charge — check your bill before adding extra. By convention (and mathematically, since you are rewarding service on the food value), tip should be calculated on the pre-GST food total, not on the final bill including GST. Example: Food total ₹1,200 + GST (5% restaurant GST) ₹60 = ₹1,260. A 10% tip on pre-GST = ₹120, not on ₹1,260 = ₹126. In practice, the difference is small, but the principle is that you are not tipping the government. The mandatory service charge (if any) is distributed among staff — unlike tips, it cannot be refused legally as per the 2022 guidelines.