Percentage Calculator — Fast & Simple
Calculate percentage, percentage increase, decrease, and difference. Easy to use online tool for all your percentage calculations.
What is P% of X?
%
Result: 15
X is what % of Y?
Result: 20%
Percentage Change (Increase/Decrease)
Percentage Increase: 20%
Percentage Formulas
P% of X = (P/100) × X X is P% of Y = (X/Y) × 100 Change % = ((New-Old)/Old) × 100 Frequently Asked Questions
- To calculate a percentage, divide the part by the whole and multiply by 100. Formula: (Part ÷ Whole) × 100 = Percentage. For example, if you got 40 questions right out of 50, your score is (40 ÷ 50) × 100 = 80%.
- To find the percentage increase: ((New Value − Old Value) ÷ Old Value) × 100. If a price goes from $50 to $75, the increase is (($75 − $50) ÷ $50) × 100 = 50%. This shows how much the value grew relative to its starting point.
- The formula is: ((Old Value − New Value) ÷ Old Value) × 100. Alternatively, use the increase formula; a negative result indicates a decrease. If a $100 item is now $80, the decrease is (($100 − $80) ÷ $100) × 100 = 20%.
- Multiply the number by the percentage expressed as a decimal (percentage ÷ 100). Formula: Number × (Percentage ÷ 100). Example: To find 15% of $80, calculate 80 × 0.15 = $12.
- In Excel, use the formula
=part/totaland then click the 'Percent Style' button in the Home tab. To calculate a 15% tip on a value in cell A1, use=A1*0.15. Excel automatically handles the decimal conversion when using the percentage format. - A percentage reflects a rate of change, while a percentage point is the arithmetic difference between two percentages. If an interest rate rises from 5% to 6%, it has increased by 1 percentage point, but the percentage increase is 20% (1 ÷ 5).
- Percentage change = (Absolute Change ÷ Original Value) × 100. It is the most common way to describe how much a value has increased or decreased over time. Use this for stock prices, population growth, or salary raises.
- Multiply the two percentages together as decimals. Example: 50% of 20% is 0.50 × 0.20 = 0.10, which is 10%. This is often used in probability or when calculating multi-stage discounts.
- To find the original value after a percentage change: Original = New Value ÷ (1 ± Rate). If a $120 item includes 20% tax, the pre-tax price = $120 ÷ 1.20 = $100. If an item is $80 after a 20% discount, the original price = $80 ÷ 0.80 = $100.
- (Obtained Marks ÷ Total Marks) × 100. If a student scores 450 out of 600, the percentage = (450 ÷ 600) × 100 = 75%. This is the standard way to report academic performance in many school systems.