How do I calculate percentage increase or decrease?

Switch to the % Change tab, enter your old and new values, and the tool automatically calculates the percentage change using ((New − Old) ÷ Old) × 100, showing whether it's an increase or decrease.

Can I use this for calculating discounts while shopping?

Yes, the Basic % mode is perfect for calculating discount amounts, and Reverse % mode can find the original price before a discount was applied.

Percentage Calculator

Basic %, Change, Reverse, Marks, Difference/Decimal/Fraction Convert, and Overall Result — 6 tools in one.

Percentage (%)

Of Value

Quick %

Result

Free Percentage Calculator — 6 Tools in One: Basic, Change, Reverse, Marks, Convert & Overall

Percentages are everywhere — shopping discounts, exam scores, salary raises, business growth reports, and more. Our free Percentage Calculator combines six essential calculation modes into a single, easy-to-use tool: Basic percentage, Percentage Change, Reverse Percentage, Student Marks Percentage, quick Conversions (difference, decimal, fraction), and Overall Result across multiple subjects.

Whether you're a student checking exam results, a shopper calculating a discount, or a business owner tracking growth, this tool gives you instant, accurate results with the formula shown for full transparency.

Why Use This Percentage Calculator?

6-in-1 tool: No need for separate calculators — Basic, Change, Reverse, Marks, Convert, and Overall modes are all in one place.
Built for students: Marks mode shows your exam percentage and grade; Overall mode totals multiple subjects at once.
Handy conversions: Percentage difference, decimal, and fraction conversions in one compact panel.
Formula transparency: See exactly which formula was used for every calculation.
Quick shortcuts: One-click buttons for common percentages like 5%, 10%, 25%, and 50%.
Color-coded results: Percentage change and grade results use color for instant clarity.

How to Use the Percentage Calculator

Basic Mode: Enter a percentage and a value to find X% of Y (e.g., 20% of 500 = 100).

Change Mode: Enter an old value and a new value to see the percentage increase or decrease between them.

Reverse Mode: Enter the final value and the percentage that was applied to find the original value before the change.

Marks Mode: Enter your obtained marks and total marks (e.g. 450 out of 500) to instantly see your percentage and letter grade.

Convert Mode: Find the percentage difference between two values, or switch between percentage, decimal, and fraction formats instantly.

Overall Mode: Add each subject's obtained and total marks to get your combined overall percentage and grade across all subjects.

Common Use Cases

Calculating shopping discounts and sale prices
Finding percentage increase in salary, rent, or prices
Working out exam scores, test results, and overall report card percentages
Business profit/loss and growth percentage analysis
Finding the original price before a discount was applied
Converting between percentages, decimals, and fractions for homework or spreadsheets

Privacy & Security

All calculations run locally in your browser. No data is uploaded, and your calculation history is stored only in your own browser's local storage.

Formulas Used

Basic: Result = (Percentage ÷ 100) × Value
Change: % Change = ((New − Old) ÷ Old) × 100
Reverse: Original = Final × 100 ÷ (100 ± Percentage)
Marks: Percentage = (Obtained Marks ÷ Total Marks) × 100
Difference: |A − B| ÷ Average(A, B) × 100
Overall: Sum of all Obtained Marks ÷ Sum of all Total Marks × 100

Frequently Asked Questions

What is reverse percentage calculation? +

It finds the original value before a percentage increase or decrease was applied — useful for figuring out a pre-discount price.

How do I calculate percentage increase? +

Switch to the "% Change" tab, enter your old and new values, and the tool shows the increase or decrease automatically.

How do I calculate what percentage one number is of another? +

Use Marks % mode: enter the smaller number as "Obtained" and the larger as "Total" to get (Obtained ÷ Total) × 100.

How do I calculate my exam percentage from marks? +

Switch to "Marks %" mode, enter your obtained marks and total marks — the tool instantly shows your percentage and letter grade.

How do I calculate my overall percentage across multiple subjects? +

Switch to "Overall %" mode, add each subject with its obtained and total marks, then click Calculate — the tool sums everything and shows your combined percentage and grade.

What is percentage difference vs percentage change? +

Percentage change treats one value as the "original" (Old vs New). Percentage difference treats both values equally, using their average as the base — useful when neither number is clearly the starting point.

How do I convert a percentage to a decimal or fraction? +

Use "Convert" mode — enter a percentage to instantly see its decimal and simplified fraction equivalents, or enter a fraction to see its percentage.

Is this percentage calculator free? +

Yes, completely free with unlimited calculations.

Can I use this for shopping discounts? +

Yes, Basic % mode calculates discount amounts, and Reverse % finds pre-discount prices.

What happens if the base value is zero? +

Percentage change can't be calculated when the old value is zero — the tool will alert you.

Can percentage change be negative? +

Yes, a negative result indicates a decrease.

Does this tool save my calculation history? +

Yes, recent calculations are saved in your browser's local storage.

Ready to calculate? Choose a mode above and get your instant, free result.

Share Your Experience

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