Percentage Calculator – Find %, Increase, Decrease & What % of Number | Free

General Math & Utility · Essential Tool

Percentage Calculator — Find %, Increase, Decrease & More Instantly

The percentage calculator is one of the most used math tools in daily life — for students, business owners, shoppers, and professionals alike. Whether you need to find what percentage of a number is, calculate a percentage increase or decrease, work out what percent X is of Y, compute a reverse percentage, find percentage change between two values, calculate a discount percentage, or convert marks to percentage — this free all-in-one percentage calculator does it all. Fast, accurate, and mobile-friendly. No app needed.

Percentage Calculator

Choose your calculation type and get instant results

Percentage (%)

Of Number

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RESULT

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How To Use

Step-by-Step: How to Use the Percentage Calculator

Choose Your Calculation Type

Select from 6 modes: “% of Number” for finding what a percentage of a value is, “X is what % of Y” for ratio calculations, “% Increase/Decrease” for change analysis, “Discount” for shopping, “Marks to %” for exam results, or “Reverse %” for reverse calculations.

Enter Your Values

Fill in the input fields with your numbers. All inputs accept decimals — so you can calculate 12.5% of 347.80 or any fractional percentage with full precision.

Click Calculate

Get your result instantly — no page reload, no waiting. Results show the main answer plus additional context like grade, CGPA equivalent, savings amount, or type of change.

Switch Modes Anytime

Use all 6 calculation types on the same page — no need to visit different websites for different percentage calculations. Everything is available in one place.

Formula

Percentage Calculator Formulas — All 6 Types

% of Number: Answer = (Percentage ÷ 100) × Number
X is what % of Y: % = (X ÷ Y) × 100
% Change: Change% = ((New−Old) ÷ Old) × 100
Discount: Final = Price × (1 − Discount%/100)
Marks to %: % = (Marks ÷ Total) × 100
Reverse %: Original = Value ÷ (Percentage ÷ 100)

Quick Examples:
15% of 200 = (15/100) × 200 = 30
45 is what % of 180? = (45/180) × 100 = 25%
100 to 125 = ((125−100)/100) × 100 = 25% increase
₹1000 at 20% discount = 1000 × 0.80 = ₹800

Smart Features

Why This Percentage Calculator is the Best

6 Calculation Modes

One tool covers all percentage needs — % of number, what % is X of Y, increase/decrease, discount, marks conversion, and reverse percentage. No need to switch between different websites.

Marks to % with CGPA

The marks-to-percentage mode also shows your CGPA equivalent (÷9.5 CBSE formula) and letter grade — giving students everything they need for forms and applications in one result.

Decimal Precision

Handles any decimal value — 12.5%, 33.33%, 7.85 — with full floating point accuracy. Results rounded to 2 decimal places for clean, readable outputs every time.

FAQ

Percentage Calculator — Frequently Asked Questions

How to calculate percentage of marks?

Percentage of marks = (Marks Obtained ÷ Total Marks) × 100. Example: 450 out of 600 = (450/600) × 100 = 75%. Use the “Marks to %” tab in our calculator above — it also shows your CGPA and letter grade automatically alongside the percentage.

How to calculate percentage increase or decrease?

Percentage change = ((New Value − Old Value) ÷ Old Value) × 100. If the result is positive it’s an increase; if negative it’s a decrease. Example: Price went from ₹80 to ₹100 → ((100−80)/80) × 100 = 25% increase. Use the “% Increase/Decrease” tab for instant results.

How to find what percentage X is of Y?

Formula: Percentage = (X ÷ Y) × 100. Example: 45 is what percent of 180? = (45 ÷ 180) × 100 = 25%. This is useful for calculating your score percentage, market share, or any ratio as a percentage. Use the “X is what % of Y” tab above for instant calculation.

How to calculate discount percentage?

Final price after discount = Original Price × (1 − Discount%/100). Example: ₹1200 at 25% off = 1200 × 0.75 = ₹900 (saving ₹300). Use our Discount Calculator tab — enter the original price and discount percentage to instantly see the final price and savings amount in rupees.

What is reverse percentage calculation?

Reverse percentage finds the original number when you know only a part and its percentage. Formula: Original = Known Value ÷ (Percentage / 100). Example: 60 is 30% of what number? = 60 ÷ 0.30 = 200. Use the “Reverse %” tab — enter the known value and the percentage it represents to find the original total.

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Conclusion

Every Percentage Calculation — One Free Tool

From basic percentage of a number to complex reverse percentage calculations, from marks to percentage for exam results to discount calculator for shopping — this free percentage calculator covers every scenario in one place. Fast, accurate, mobile-friendly, and always free. Bookmark it and use it daily.

Percentage calculator