CalcQuick guides
Calculator guides
Short, practical explanations for the assumptions behind everyday calculations.
How to Calculate TDEE: Formula, Activity Levels and Limits
A practical guide to estimating total daily energy expenditure from BMR and an activity multiplier.
Macros for Beginners: Protein, Carbs and Fat Explained
Learn how calorie percentages become daily grams of protein, carbohydrates and fat.
Hourly Pay vs Salary: How to Compare Gross Compensation
Convert hourly and annual gross pay using work hours, paid weeks and a consistent comparison.
How to Count Business Days: Weekends, Holidays and Examples
Count business days step by step, exclude custom holidays and add workdays to a date with a free calculator. Includes a worked calendar example.
BMI vs Body Fat: What Each Number Can and Cannot Tell You
Understand the difference between an adult BMI screening ratio and a body-fat estimate.
Percentage Change vs Percentage Difference: Which Formula to Use?
Choose the correct percentage formula by separating directional change from a symmetric comparison.
Compound Interest with Monthly Contributions: Formula and Timing
Understand how a starting balance, compounding frequency and beginning- or end-of-month deposits build a projection.
Monthly Savings Goal: How Much Do You Need to Save?
Work backward from a target balance to an estimated fixed monthly contribution.
APY vs Interest Rate: How Compounding Changes the Annual Yield
Compare a nominal annual interest rate with the one-year effective yield created by compounding.