A $300,000 loan at 6.5% over 30 years costs $1,896.20 a month in principal and interest. This guide explains the formula step by step, how amortization works, what PITI and PMI add, and why a 15-year loan saves over $212,000 in interest.
BMI is your weight divided by your height squared. This guide shows both formulas, works through verified examples, explains the CDC categories, and covers BMI’s limits — plus when body fat percentage tells you more.
Learn how to calculate a tip with the percentage formula, verified worked examples, US tipping norms by service, and how to split a bill fairly.
Learn how to calculate standard deviation step by step, with population vs sample formulas, two fully worked examples, and Excel, Sheets, and Python methods.
Learn how to calculate GPA step by step: the 4.0 scale, quality points formula, a worked example (3.45 GPA), weighted vs unweighted, and semester vs cumulative GPA.