How do I calculate X% of Y?

Multiply Y by X and divide by 100. For example, 20% of 150 = (150 × 20) / 100 = 30.

How do I calculate percentage change?

Percentage change = ((New − Old) / |Old|) × 100. A positive result is an increase; negative is a decrease.

How do I find what percentage X is of Y?

Divide X by Y and multiply by 100. For example, 30 is what % of 150? = (30 / 150) × 100 = 20%.

How do I calculate a discount amount?

Use the 'What is X% of Y?' calculator. Enter the discount percentage as X and the original price as Y. The result is the amount to subtract from the price. For example, 20% of 500 = 100, so the discounted price is 400.

How do I calculate percentage increase or decrease?

Use the percentage change calculator. Enter the original value and the new value. A positive result means an increase; a negative result means a decrease. For example, going from 80 to 100 is a 25% increase.

Private by defaultRuns in your browser

Percentage calculator

Pick the percentage formula you need, enter your numbers, and get the result instantly — no formula memorisation required.

What is X% of Y?

Percentage (X)

Number (Y)

Quick samplesUseful for testing

Percentage Calc

About this tool

Find X% of Y, what percent X is of Y, or calculate percentage increase/decrease instantly. Works in your browser — no signup, no ads.

Pick the percentage formula you need, enter your numbers, and get the result instantly — no formula memorisation required.

No signup requiredRuns in your browserInstant results

How to use

1
Choose the type of percentage calculation: percentage of a number, percentage change, or what percentage one number is of another.
2
Enter your values — the result updates instantly.
3
Use the percentage increase/decrease mode to calculate discounts, tax, or growth rates.

Why use this tool?

→
Calculate discounts, tips, and tax amounts on prices.
→
Find the percentage change between two values for reports or dashboards.
→
Determine what percentage one number is of another for data analysis.

ExamplesInput → output

Percentage of a number

Input15% of 200

Output30

Percentage change

InputFrom 80 to 100

Output25% increase

What percent

Input45 is what % of 180

Output25%

Frequently asked questionsCommon questions answered

These answers explain common percentage calc tasks, expected input formats, and edge cases so both visitors and search engines can understand what this tool does.

How do I calculate X% of Y?: Multiply Y by X and divide by 100. For example, 20% of 150 = (150 × 20) / 100 = 30.
How do I calculate percentage change?: Percentage change = ((New − Old) / |Old|) × 100. A positive result is an increase; negative is a decrease.
How do I find what percentage X is of Y?: Divide X by Y and multiply by 100. For example, 30 is what % of 150? = (30 / 150) × 100 = 20%.
How do I calculate a discount amount?: Use the 'What is X% of Y?' calculator. Enter the discount percentage as X and the original price as Y. The result is the amount to subtract from the price. For example, 20% of 500 = 100, so the discounted price is 400.
How do I calculate percentage increase or decrease?: Use the percentage change calculator. Enter the original value and the new value. A positive result means an increase; a negative result means a decrease. For example, going from 80 to 100 is a 25% increase.