Blog
Practical, accurate guides on percentages — formulas, worked examples, and the calculations people get wrong most often.
Percentage Points vs. Percent: What’s the Difference?
Learn the difference between percentage points and percent change with simple examples from finance, business, statistics, and everyday calculations.
Percentage Change vs. Percentage Difference: What’s the Difference?
Learn when to use percentage change and percentage difference, including formulas, examples, and practical situations where the two calculations differ.
Why a 20% Increase and a 20% Decrease Don’t Cancel Out
A 20% increase followed by a 20% decrease does not return you to the original value. Learn why with simple examples and calculations.
How Percentage Discounts Work
Learn how percentage discounts work, how to calculate the discount amount and final sale price, and how multiple discounts affect the final price.
How to Find the Original Price After a Discount
Learn how to calculate the original price when you know the sale price and discount percentage, with formulas and worked examples.
Markup vs. Margin: What’s the Difference?
Markup and margin both measure profitability, but they use different bases. Learn the formulas, examples, and difference between markup and profit margin.
How to Calculate Year-over-Year Growth
Learn how to calculate year-over-year growth with the formula, examples, negative growth, and practical business applications.
What Is Percentage Error and How Is It Calculated?
Learn what percentage error means, how to calculate it, and how absolute error, relative error, and percentage error differ.
How Percentage Distribution Works
Learn how percentage distribution works, how to calculate each category’s share of a total, and how to check whether your percentages are correct.
Common Percentage Calculation Mistakes
Learn the most common percentage mistakes, including incorrect bases, confusing percentage points with percent change, and reversing discounts incorrectly.