Are these tools regulated as medical devices?

No. They are general-purpose calculators that compute published formulas. They are not diagnostic tools, they do not store your inputs, and they are not a substitute for a qualified clinician. In the UK they fall outside the MHRA definition of medical software; in the US they are similarly outside the FDA "device" definition because they do not diagnose, treat or prescribe.

Which numbers should I actually track over time?

For most healthy adults, weight (weekly average, not daily), waist circumference, resting heart rate and sleep duration will tell you more about long-term health than BMI or body fat alone. Track any of those on a fortnightly cadence rather than reacting to single readings.

Why does the calorie calculator give a different number to the app on my watch?

Consumer wearables use proprietary formulas plus movement data. Our calculator uses the peer-reviewed Mifflin-St Jeor equation with activity multipliers from the WHO physical-activity levels table. The two will not match, and neither is "wrong" — they are different models. Use one consistently for tracking; do not mix.

Health & Fitness

Health and fitness calculators that turn published clinical formulas — BMI, Mifflin-St Jeor BMR, the U.S. Navy circumference method for body fat, the 90-minute sleep-cycle model — into one-screen answers you can act on today. Every tool cites its source on the About panel; you should verify anything a result surprises you with, against a clinician who knows your history.

About health & fitness on Dailiyo

Health calculators live in an awkward place: the maths is usually simple, but the interpretation is not. Take BMI — a number invented in 1832 by a Belgian astronomer as a population-level statistic, later adopted by the World Health Organization as a screening threshold, and now routinely mis-cited as a diagnostic. Our tools compute the number that a professional would compute, and then say plainly what the number does and does not mean. If a page tells you your BMI is 27 without also explaining that muscle mass, age, ethnicity and body composition all change what that means for you, it is under-serving you.

Everything on these pages is designed to be safe to reason with on your own. The calorie tools use Mifflin-St Jeor because the Academy of Nutrition and Dietetics has recommended it since 2005 as the most accurate general-purpose equation for healthy adults; the body-fat tool uses the Navy circumference method because it is the accessible-at-home version of DEXA that professional strength coaches trust for tracking trend; the pregnancy due-date tool uses the standard 40-week rule from last menstrual period (Naegele's rule), which is what the majority of maternity units in the UK, US and Australia use.

Where a number can be genuinely misleading — BMI for athletes, body fat for pregnant women, calorie targets for people with eating-disorder history — we flag it inline on the tool rather than burying the caveat in a disclaimer. If you have a chronic condition, are on medication, or are pregnant or nursing, please treat these calculators as a starting point for a conversation with your clinician, not as a substitute for one.

Health & Fitness tools (12)

BMI Calculator — Free BMI calculator. Enter your height and weight to find your Body Mass Index and category — works in metric and imperial units.
Ideal Weight Calculator — Find a healthy ideal weight range from your height using Devine, Robinson and BMI methods.
Body Fat Percentage Calculator — Detailed body fat percentage calculator using neck, waist and hip measurements with charts.
Smart Calorie Calculator (BMR & TDEE) — Get BMR, TDEE and daily macro split in one go. Built for cutting, bulking and maintenance.
Water Intake Calculator — How much water should you drink each day? Personalized estimate by weight, climate and activity.
Calories Count Calculator — Add common foods and get a quick total calorie count for the meal or day.
Walk to Lose Weight Calculator — How long do you need to walk to lose a kilo? Calculate steps, distance and calories burned.
Sleep Cycle Calculator — Find the perfect bedtime or wake-up time based on 90-minute sleep cycles.
Pregnancy Due Date Calculator — Estimate your due date and current week of pregnancy from your last period date.
Weight & Diet Chart — Generate a balanced 7-day diet chart based on your weight, goal and food preference.
Weight & Workout Plan — Build a weekly home or gym workout plan tailored to your fitness level and goal.
Recipe Calculator — Scale a recipe up or down by servings and see total calories, protein, carbs and fat.

Frequently asked questions

Are these tools regulated as medical devices?: No. They are general-purpose calculators that compute published formulas. They are not diagnostic tools, they do not store your inputs, and they are not a substitute for a qualified clinician. In the UK they fall outside the MHRA definition of medical software; in the US they are similarly outside the FDA "device" definition because they do not diagnose, treat or prescribe.
Which numbers should I actually track over time?: For most healthy adults, weight (weekly average, not daily), waist circumference, resting heart rate and sleep duration will tell you more about long-term health than BMI or body fat alone. Track any of those on a fortnightly cadence rather than reacting to single readings.
Why does the calorie calculator give a different number to the app on my watch?: Consumer wearables use proprietary formulas plus movement data. Our calculator uses the peer-reviewed Mifflin-St Jeor equation with activity multipliers from the WHO physical-activity levels table. The two will not match, and neither is "wrong" — they are different models. Use one consistently for tracking; do not mix.

All health & fitness tools on Dailiyo are hand-written and reviewed at least annually. If you spot an error or would like us to build a specific health & fitness tool that is missing, email info@dailiyo.xyz or use the Contact page.