Guides
Health, explained in plain English.
Short, practical guides to the numbers people care about — what they mean, how to use them, and where they fall short. Each one is backed by a free calculator.
How to Calculate Your Exact Age
Your age is more than a number of years. Learn how to work out the exact years, months and days — leap years included.
Read guideWhat Your BMI Really Tells You (and What It Doesn't)
BMI is a quick screen, not a verdict. Learn what it measures, what the categories mean, and where it falls short.
Read guideWhat Is BMR and Why It's the Base of Every Calorie Plan
BMR is the calories you'd burn doing nothing all day. Learn why it's the foundation of any calorie plan.
Read guideHow to Estimate Body Fat at Home
You don't need a lab to track body fat. Learn the tape method, how to measure right, and how accurate it really is.
Read guideHow Many Calories Should You Eat to Lose Weight?
Weight loss runs on a calorie deficit. Learn how to set a target that works without starving yourself.
Read guideHow a Calorie Deficit Works for Weight Loss
Every diet that works runs on a calorie deficit. Learn how it drives fat loss and how to set a safe pace.
Read guideHow Many Calories Does Your Workout Burn?
Workout calorie counts are estimates, not gospel. Learn how MET values work and why your tracker may differ.
Read guideHow Your Pregnancy Due Date Is Calculated
Your due date is an estimate, not a deadline. Learn how it's calculated and why few babies actually arrive on it.
Read guideIs There Really an Ideal Weight?
There's no single perfect number. Learn what ideal-weight formulas mean and why a healthy range is the better goal.
Read guideLean Body Mass: Why It Matters More Than Weight
Lean mass is everything that isn't fat. Learn why protecting it is the real goal of any healthy diet.
Read guideHow to Set Your Macros for Any Goal
Macros are just protein, carbs and fat. Learn how to split your calories in a way that fits your goal.
Read guideHow to Estimate Your One-Rep Max Safely
You don't have to max out to know your 1RM. Learn how to estimate it from a normal set and train off it.
Read guideHow to Find Your Fertile Window
Conception has a window, not a single day. Learn how to estimate yours — and why calendars can only do so much.
Read guideHow to Calculate and Use Your Running Pace
Pace is the runner's core number. Learn how to calculate it and use it to run smarter races and workouts.
Read guideHow Much Weight to Gain in Pregnancy
Healthy pregnancy gain depends on where you start. Learn the IOM ranges and how gain spreads across the trimesters.
Read guideHow Much Protein Do You Really Need?
Protein needs depend on what you're doing. Learn the ranges for health, training and building muscle.
Read guideHeart Rate Zones: How to Train at the Right Intensity
Training by heart rate keeps you honest. Learn what each zone trains and how to find your max.
Read guideTDEE: How Many Calories You Actually Burn in a Day
TDEE is your real daily calorie burn. Learn how activity multiplies your BMR and how to pick your level honestly.
Read guideWhat Your Waist-to-Hip Ratio Says About Your Health
Where you carry fat matters as much as how much. Learn what your waist-to-hip ratio reveals that BMI misses.
Read guideHow Much Water Should You Drink a Day?
Forget the rigid 8-glass rule. Learn what actually drives your water needs and how to tell if you're hydrated.
Read guideSkip the reading — just run the numbers
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