Clear explanations of the formulas behind everyday health numbers, from blood alcohol concentration and testosterone levels to macro needs, FFMI, and how PCOS changes calorie math.
A lot of health advice skips the formula and jumps straight to the recommendation. This category does the opposite. Each guide takes a number people commonly look up, whether that's blood alcohol concentration, a testosterone reading, or a daily protein target, and shows exactly how it's calculated and what the inputs mean.
You'll find guides comparing free, total, and bioavailable testosterone, explaining what fat-free mass index measures and how it differs from BMI, and walking through how PCOS changes calorie needs and calorie-deficit strategy. There are also practical breakdowns of how BAC is calculated after drinking and how to work out your own daily macro and protein needs instead of copying a generic number off the internet.
The goal is to make you a more informed reader of your own lab results, body composition metrics, and everyday health calculators, not to replace medical advice. If a number in one of these guides looks off for your situation, that's worth bringing to a doctor or registered dietitian, and several articles point out exactly where individual variation matters most.
10 in-depth guides, updated regularly.
Common Health Guide
Learn safe, sustainable calorie deficit strategies for PCOS, with realistic weight-loss goals, macros, a sample meal plan, and exercise tips inside.
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Common Health Guide
See the six main factors that affect your BAC level, plus real BAC ranges, current legal limits, and why there's no fast way to lower it once it's up.
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Common Health Guide
BMI often mislabels muscular people as overweight. Learn what FFMI measures, how to calculate your Fat-Free Mass Index, and which metric fits your goals.
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Common Health Guide
Learn the real differences between free, total, and bioavailable testosterone, see example reference ranges, and find out which number actually matters most.
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Common Health Guide
Learn how blood alcohol concentration (BAC) is calculated, what BAC levels like 0.08% and 0.15% mean, and how many drinks it takes to reach them.
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Common Health Guide
Find out exactly how much protein you need per day for your weight, muscle goals, or weight loss, plus real food examples to help you hit your target.
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Common Health Guide
PCOS often makes weight loss harder due to insulin resistance and hormone shifts. Learn how it affects calorie needs and how to lose weight safely.
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Common Health Guide
Learn what Fat-Free Mass Index (FFMI) measures, how it compares to BMI, and what a normal FFMI range looks like for men and women, with a free calculator.
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Common Health Guide
Learn what bioavailable testosterone means, how it's calculated, and what your levels could indicate for men and women. Includes a free calculator.
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Common Health Guide
Learn how to calculate your daily macro and protein needs with simple formulas, food examples, and the updated 2026 U.S. protein guidelines explained.
Read MoreEvery guide breaks down the calculation behind the number instead of handing you a result with no explanation.
We flag where individual variation matters most, so you know when a number is worth discussing with a doctor or dietitian.
BAC, FFMI, and macro estimates all have real limits. These guides explain them instead of overstating precision.
Body composition and metabolic guidance shifts over time, so these articles are revisited as the evidence updates.
Put what you just read into practice, try these free tools instantly, no sign-up required.
Measure your lean muscle mass relative to height with FFMI.
Calculate your daily protein, carbs, and fat intake targets.
Estimate your blood alcohol concentration based on drinks consumed.
Calculate free and bioavailable testosterone levels from lab results.
Plan a sustainable calorie deficit tailored for managing PCOS.