Mathematics

Percentage Calculator

Calculate a discount, compare changes, or find any percentage.

About this tool

Percentage Calculator calculates results in your browser. Check important financial, medical, or planning decisions with an appropriate professional.

GUIDE

How to use this calculator

This percentage calculator is structured for common searches: percent of a number, percent change, and value-to-total comparisons. It is useful for discounts, exam scores, growth rates, and quick finance checks.

Calculation method

Percentage = part ÷ whole × 100; percentage change = (new value − old value) ÷ old value × 100

Quick examples

20% of 150 = 30
80 is 40% of 200
50 to 65 = 30% increase
25% off 120 = 90

Steps

Choose the percentage question that matches your task.
Enter the part and whole, or the starting and ending values.
Read the instant percentage result.
Use the example formulas to confirm the calculation method.

How do I calculate a test percentage?

Enter the score as the part and the total possible score as the whole. The result is the percentage grade.

How do I calculate percentage increase?

Enter the old value as From and the new value as To. Positive output is an increase; negative output is a decrease.

Does this work for discounts?

Yes. Use the examples to calculate the discounted amount or the final price.

EXAM SCORE GUIDETest score percentage PERCENT CHANGE GUIDEPercentage increase DISCOUNT GUIDEDiscount and sale price

Percentage calculator

Work out proportions and compare change.

What percentage is a value?

PartWhole

PERCENTAGE12.5%

Percentage change

FromTo

CHANGE+25%

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