Percentage calculator
Find the % of an amount, what % one number is of another, or the percentage change between two values.
What is the % of an amount?
- 20% of 100
- 20
What % is one number of another?
- Percentage
- 20%
Percentage change between two values
- Increase
- 20%
How the percentage is calculated
The percentage of an amount is found by multiplying that amount by the percentage expressed as a decimal:
result = (percentage ÷ 100) × amount
To find what percentage a number represents of a total, divide the number by the total and multiply by 100:
percentage = (number ÷ total) × 100
The percentage change between two values compares the final value with the initial value:
change = ((final value − initial value) ÷ initial value) × 100
Worked example
If a product costs $100 and has a 20% discount, the discount is (20 ÷ 100) × 100 = $20, so the final price is $80. If that same product later rises from $80 to $96, the percentage change is ((96 − 80) ÷ 80) × 100 = 20%.
Frequently asked questions
- How do I calculate 20% of a number?
- Multiply the number by 20 and divide by 100. For example, 20% of 100 is 20.
- How do I find what percentage one number is of another?
- Divide the number by the total and multiply by 100. For example, 20 out of 100 is 20%.
- How is a percentage increase or decrease calculated?
- Subtract the initial value from the final value, divide by the initial value, and multiply by 100. A positive result means an increase, a negative one a decrease.
- Can the result have decimals?
- Yes, the calculator shows up to 4 decimal places to keep results precise for non-round figures.
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