Free Online Percentage Calculator
Easily compute basic percentages, percentage increases, decreases, discounts, and exam marks. Learn every percentage formula step-by-step.
Need full scientific functions too? Switch over to the Casio Scientific Calculator Online for trigonometry, logarithms, and more.
What Is the Basic Percentage Formula?
The core percentage formula calculates the relative portion of a whole amount converted to a base of 100:
(45 ÷ 60) × 100 = 75%Your score is 75%.
Quick Percentage Reference
| What you want to calculate | Percentage Formula |
|---|---|
| Basic percentage | (Part ÷ Whole) × 100 |
| Percentage of a number | (Percentage ÷ 100) × Number |
| Percentage of marks | (Marks obtained ÷ Total marks) × 100 |
| Percentage change | ((New − Old) ÷ Old) × 100 |
| Percentage increase | (Increase ÷ Original) × 100 |
| Percentage decrease | (Decrease ÷ Original) × 100 |
| Discount percentage | ((Original − Sale) ÷ Original) × 100 |
| Profit percentage / markup | (Profit ÷ Cost) × 100 |
Multiple Percentage Calculation Modes
Basic Percentage
Calculate what percentage one number is of another, ideal for test marks and general ratios.
Percentage Change
Determine exact percentage increase or decrease between two values over time.
Discounts & Shopping
Quickly find final sale prices, discount rates, and money saved during store sales.
Frequently Asked Questions
How is percentage calculated?
Percentage is calculated by dividing the part by the total whole value, then multiplying by 100.
What is the formula for percentage increase?
Percentage Increase = ((New Value - Original Value) ÷ Original Value) × 100.
How do you calculate a percentage of a number?
Multiply the number by the percentage converted to a decimal (e.g., 20% of 150 = 0.20 × 150 = 30).
How do I calculate percentage decrease?
Percentage Decrease = ((Original Value - New Value) ÷ Original Value) × 100.
How do you find the percentage of exam marks?
Divide total obtained marks by total maximum marks, then multiply by 100.
How do I calculate discount percentage on an item?
Discount % = ((Original Price - Sale Price) ÷ Original Price) × 100.
How do you reverse calculate a percentage?
Original Value = Part Value ÷ (Percentage ÷ 100).
Is profit percentage calculated on cost or selling price?
Profit percentage (markup) is calculated on cost price, while profit margin is calculated on selling price.