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Percentage calculator tool supporting common scenarios like percentage increase/decrease and discounts.
Enter values to start calculating
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Circle Area Calculator
Quickly calculate the area of a circle by entering the radius, diameter, or circumference. Supports custom units and precision settings.
Inverse Trigonometric Function Calculator
Accurately calculate radian values for inverse trig functions like arcsin and arccos. Supports 6 function types and custom decimal precision.
Least Common Multiple (LCM) Calculator
Quickly calculate the least common multiple (LCM) of two or more integers. Supports space-separated number list input.
Prime and Composite Number Calculator
Instantly identify prime, composite, or special numbers. Supports batch checking and mathematical property analysis.
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Whether you need to quickly calculate product discounts, grade proportions, or performance growth, calculating percentages is a fundamental yet error-prone mathematical operation. This tool uses standardized formulas to handle four core calculation scenarios: finding a proportion (what percentage of B is A), finding a percentage value (what is B% of A), calculating percentage increase/decrease (the result after adding/subtracting B%), and reverse calculation (what is the total if A% is B). A percentage essentially standardizes any value by converting it into a "proportion per 100 units" for easy comparison.
How do I calculate the final price of a $300 item with a 20% discount?
Use the "Percentage Decrease" mode: Enter A=300 and B=20. The result, $240, is your discounted price.
What is the difference between a percentage and a percentage point?
A percentage is a relative change based on the original value (e.g., a 10% increase), while a percentage point is an absolute difference (e.g., an interest rate rising from 5% to 7% is an increase of 2 percentage points). This tool only handles percentage calculations.
When entering a percentage, only input the numeric part (e.g., enter 15 for 15%). Manual verification is recommended for financial scenarios. Batch calculations must be performed one by one.
In statistical reports, it is recommended to display both the percentage and the raw value. When the base number is very small (e.g., 2/3 ≈ 66.7%), showing only the percentage can exaggerate the perception of variance. For example: When calculating the proportion of 3 people in a 5-person team, displaying "60% (3/5)" is much more rigorous than just "60%".
