Percentage Calculator
Calculate percentages, increases, decreases, and percentage change with a clear explanation.
Result
Enter the values to calculate.
How to calculate a percentage of a value
To find X% of an amount, convert the percentage to a decimal and multiply it by the value. For example, 20% of 500 is 100.
Result = (percentage ÷ 100) × value
What percentage one number is of another
Divide the part by the total and multiply by 100. The total or reference value cannot be zero.
Percentage = part ÷ total × 100
Percentage increases and decreases
An increase adds the selected proportion to the starting value; a decrease subtracts it. Negative percentages are mathematically valid and reverse the usual effect.
Final value = starting value × (1 ± percentage ÷ 100)
How to calculate percentage change
Percentage change compares the difference with the old value. A positive result is an increase and a negative result is a decrease.
Change (%) = (new − old) ÷ old × 100
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