Percentage Calculator

Percent of a number, ratios and increase / decrease.

Solve the three everyday percentage questions: what is X% of a number, what percent one number is of another, and the percentage increase or decrease between two numbers. Perfect for marks, discounts, tips, tax and growth rates. Runs fully in your browser — nothing is uploaded.

How to use Percentage Calculator

  1. Choose a mode

    Select one of three modes in this free online percentage calculator: percent of a number, X is what percent of Y, or percent increase and decrease.

  2. Enter the first value

    Type the first number, whether it is the percentage, the part value X, or the starting from-value, depending on the calculation mode you picked.

  3. Enter the second value

    Add the second number, such as the base value, the total Y, or the new to-value, and the percentage answer updates instantly as you type.

  4. Read the result

    Instantly see the computed result in the hero card, along with a plain-language summary of exactly what percentage or amount was calculated.

  5. Switch modes to compare

    Toggle between modes to solve discounts, marks, tips, tax or growth rates without re-entering data, making everyday percentage maths quick and easy.

  6. Share the calculation

    Use the share button to copy a link that reopens this percentage calculator with your selected mode and both entered numbers preserved.

Frequently asked questions

How do I find a percentage of a number?

Divide the percentage by 100 and multiply by the number. For example, 25% of 200 = 25 ÷ 100 × 200 = 50. Use the “% of a number” mode for this.

How is percentage increase calculated?

Subtract the old value from the new value, divide by the old value, then multiply by 100. A drop gives a negative result (a decrease). Use the “% increase / decrease” mode.

What if the total (Y) is zero?

Percentages that divide by Y (or by the old value) are undefined when it’s zero, so the result simply won’t show until you enter a non-zero value.

What percentage is X of Y?

Divide X by Y and multiply by 100: X ÷ Y × 100. For example, 25 is what percent of 200? That’s 25 ÷ 200 × 100 = 12.5%. Use the “X is what % of Y” mode in this percentage calculator to work it out instantly.

How do I calculate a discount percentage or percentage off?

To find the saving, use “% of a number” — e.g. 20% off ₹200 is 20 ÷ 100 × 200 = ₹40. To find what percent you saved between two prices, use the “% increase / decrease” mode, which is ideal for discounts, price drops and growth rates.

How do I calculate my marks percentage?

Divide your marks obtained by the total marks and multiply by 100 — for example 425 out of 500 is 425 ÷ 500 × 100 = 85%. Use the 'X is what % of Y' mode here, entering marks obtained as X and total marks as Y.

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

To add 18% GST to ₹1,000, find 18% (₹180) and add it (₹1,180); to take 20% off, find 20% and subtract. Use '% of a number' to get the amount, then add or subtract it — handy for tax, tips and discounts.

Is my data sent anywhere?

No. Everything is calculated in your browser with JavaScript — nothing you enter is uploaded.

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