What percentage modes are supported?

Percent of a value, “X is what % of Y”, percent change between two numbers, increase by a percentage, and decrease by a percentage (for discounts).

Yes. Enter decimals for both the base number and the percentage (for example 12.5%).

How is percent change calculated?

Percent change = ((new − old) ÷ |old|) × 100. A rise from 80 to 92 is a 15% increase; a drop from 100 to 80 is a −20% change.

Why is % change from zero unavailable?

Dividing by a zero starting value is undefined. Enter a non-zero “from” value, or use “% of value” / “increase by %” instead.

Is this the same as GST calculation?

No. This tool does general percentage math. For CGST/SGST/IGST illustrations, open the GST calculator and read its disclaimers.

Calculator

Percentage Calculator

Calculate percent of a value, what percentage one number is of another, percent change, or increase/decrease by a percentage. Built for discounts, marks, and everyday maths—runs locally in your browser.

Percentage modes

Find P% of a number (discounts, tips, marks).

Starting value

Percentage (%)

Result

300

15% of 200

Useful for

DiscountsMarksSalary hikesBudgets

GST calculatorIndia GST exclusive and inclusive illustrations.

EMI calculatorMonthly loan payment, interest, and total amount.

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Privacy & limitations

v1.0.0·Updated 2026-09-25

Files are processed in your browser and are not uploaded to our servers.

Your files stay on your device. We do not store or access your documents.

Guides, tips & FAQ

What is a percentage?

A percentage expresses a proportion out of 100. “15% of 200” means fifteen hundredths of 200. Percent change compares how much a value moved relative to its starting point.

Formulas

% of X = (P ÷ 100) × X | % change = ((new − old) ÷ |old|) × 100

Increase by P%: new = value × (1 + P/100). Decrease by P%: new = value × (1 − P/100). “X is what % of Y”: (X ÷ Y) × 100.

Worked example — sale price

List price ₹2,499 with 20% off.
Sale price = 2499 × (1 − 0.20) = 2499 × 0.80.
You pay ₹1,999.20; you save ₹499.80.
₹1,999.20 after 20% discount

Everyday uses

Discounts, GST add-ons, and tip estimates
Exam marks and score improvement (% change)
Salary hike or price increase scenarios
What share one expense is of a monthly budget

Notes

Percent change from zero is undefined (except 0 → 0). Results show at most two decimal places. For India GST breakup, use the GST calculator (illustrative only). Browse more terms in the glossary.

Frequently asked questions

Percentage modes

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Guides, tips & FAQ

Frequently Asked Questions