Health Calculators
The health calculators on this site turn common questions — Am I in a healthy weight range? How many calories do I need each day? When is my baby due? — into numbers you can check for yourself. Each one starts from a named formula: the World Health Organization's BMI classification, the Mifflin-St Jeor equation for basal metabolic rate, Naegele's rule for estimated due dates. None of them predicts your health outcome; they estimate where you fall against population-level reference ranges, and the calculator shows you exactly how it got there.
Body composition and calorie needs vary with age, sex, activity level, and body frame in ways a single number can't fully capture, so every health calculator here pairs its result with the formula and the inputs that produced it — not just a verdict. That's deliberate: a BMI of 24.9 and a BMI of 25.1 fall on opposite sides of a category boundary but describe almost the same body, and seeing the arithmetic makes that clear instead of hiding it behind a label.
These tools are for general information only. They don't replace a conversation with a doctor, dietitian, or midwife, and none of them account for medical history, medication, pregnancy complications, or body composition details that only a clinical assessment can capture. Use them to get a quick, transparent estimate, and treat any result that concerns you as a reason to ask a professional — not as a diagnosis. If you're pregnant, tracking a chronic condition, or making a decision that depends on the result, a clinician can factor in details these calculators simply have no way to see.
- BMI CalculatorEnter your weight and height to calculate your Body Mass Index (BMI), a quick screening measure used worldwide to estimate whether your weight falls in a healthy range for your height.Last updated 2026-08-11
- Body Fat Percentage CalculatorEnter your height, neck, waist, and (if female) hip measurements to estimate your body fat percentage using the U.S. Navy circumference method — no calipers or scans required, just a tape measure.Last updated 2026-08-11
- TDEE CalculatorEnter your sex, age, weight, height, and activity level to estimate your Total Daily Energy Expenditure (TDEE) — the number of calories your body burns in a typical day, including movement and exercise.Last updated 2026-08-11
- Due Date CalculatorEnter the first day of your last period and your average cycle length to estimate your due date, trimester milestones, and when your pregnancy reaches full term. This is a general estimate meant to support, not replace, care from your doctor or midwife.Last updated 2026-08-11
- Ovulation & Fertile Window CalculatorEnter the start date of your last period and your typical cycle length to estimate your ovulation date, fertile window, and next expected period.Last updated 2026-08-11