Percentage Points vs Percent Change: What Is the Difference?
Understand percentage points versus percent change with simple examples, formulas, and common mistakes when comparing rates and percentages.
How to Calculate Age From Date of Birth in Years, Months and Days
Find exact age from a date of birth in years, months and days. Follow a worked example and learn about month lengths, leap years and date counting.
How to Calculate GPA With Credit Hours: A 4.0 Scale Example
Learn the weighted GPA formula using course credits and grade points, with a clear 4.0-scale example and notes about different school grading rules.
How to Calculate BMI: Formula, Adult Ranges and Limitations
Learn the adult BMI formula in metric and US units, see a worked example, understand CDC adult BMI ranges, and learn what BMI cannot tell you.
How Much Concrete Do I Need for a Slab? Formula and Example
Calculate concrete for a slab using length, width and thickness. Follow a cubic-feet and cubic-yards example and learn when to allow for waste.
Compound Interest Formula: How to Calculate Monthly Compounding
Understand the compound interest formula with monthly compounding, a worked example, what each variable means, and how to estimate future value.
How to Calculate Percentage Increase: Formula and Examples
Learn how to calculate percentage increase with the correct formula, step-by-step examples, percentage decrease, and common mistakes.