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What Is a Percentage Calculator?
A percentage calculator is a tool that performs common percentage operations — finding what percent one number is of another, calculating percentage increase or decrease, and determining the result of applying a percentage to a value. These calculations appear constantly in everyday life and business.
While the math behind percentages is straightforward (a percentage is simply a fraction of 100), doing these calculations mentally or by hand is error-prone. A dedicated calculator eliminates mistakes and handles multiple calculation modes instantly.
How Percentage Calculations Work
CheckTown's percentage calculator supports several common operations.
- What is X% of Y? — multiply the value by the percentage divided by 100 (e.g., 15% of 200 = 30)
- X is what % of Y? — divide the part by the whole and multiply by 100 (e.g., 30 is 15% of 200)
- Percentage change — calculate the increase or decrease between two values as a percentage ((new - old) / old × 100)
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Calculate Percentages →When To Use a Percentage Calculator
Percentage calculations come up in almost every field.
- Shopping and finance — calculate discounts, tax amounts, tips, interest rates, and investment returns
- Data analysis — find growth rates, conversion rates, market share, and year-over-year changes
- Academic work — calculate grades, test scores, statistical percentages, and survey result distributions
Frequently Asked Questions
How do I calculate percentage increase?
Percentage increase = ((New Value - Original Value) / Original Value) × 100. For example, if a price goes from $80 to $100, the increase is ((100 - 80) / 80) × 100 = 25%. A negative result indicates a decrease.
What is the difference between percentage and percentage points?
A percentage point is an absolute difference between two percentages. If an interest rate goes from 5% to 7%, it increased by 2 percentage points but by 40% in relative terms ((7-5)/5 × 100). This distinction matters in finance and statistics.
How do I find the original price before a discount?
Divide the discounted price by (1 - discount/100). For example, if an item costs $75 after a 25% discount, the original price is $75 / (1 - 0.25) = $75 / 0.75 = $100. This reverse calculation is useful for verifying sale prices.