Numbers that care
Health
BMI and pregnancy-cycle estimates based on standard, documented methods — always labelled as estimates, never medical advice.
Pregnancy Calculator
Estimate your due date, current week and trimester from the first day of your last period.
Due Date Calculator
Your estimated due date from a last period, a conception date, an IVF transfer or an ultrasound, with the week you are in and the milestones ahead.
Ovulation Calculator
Estimate ovulation day and your fertile window from your cycle length — limitations stated honestly.
BMI Calculator
Body Mass Index with WHO category and healthy weight range for your height.
Calorie Calculator
Estimate your basal metabolic rate and daily calorie needs with the Mifflin–St Jeor equation, plus targets for losing, maintaining or gaining weight.
BMR Calculator
Your basal metabolic rate by three published equations side by side: Mifflin–St Jeor, Harris–Benedict and, with a body-fat figure, Katch–McArdle.
TDEE Calculator
Your total daily energy expenditure at your activity level, and the same body at all five levels, from the BMR equation you choose.
Sleep Calculator
Plan your bedtime or wake-up time around 90-minute sleep cycles with a 15-minute fall-asleep buffer, in either direction depending on the time of day you can hold fixed.
Macro Calculator
Estimate your BMR and TDEE with the Mifflin–St Jeor equation and split your daily calories into protein, carbohydrate and fat targets in grams.
What this covers
Body-measurement and cycle estimates built on published, named methods: BMI on the WHO adult scale, resting and daily energy from the Mifflin–St Jeor, Harris–Benedict and Katch–McArdle equations, a due date from Naegele’s rule or from a conception date, an IVF transfer or an ultrasound, and ovulation from a fixed luteal phase. Each page states the method it implements and when it was last checked.
Which tool to use
BMI and Calorie work together: BMI places a height and weight on the WHO scale, while the Calorie Calculator estimates the energy that body uses in a day and what that means for losing, holding or gaining weight. Pregnancy and Ovulation both start from the first day of the last period — use Pregnancy once you are expecting and want a due date and week, and Ovulation when you are tracking a cycle and want the fertile window. For the energy figures on their own, BMR compares three published equations for a body at rest and TDEE shows the same body at all five activity levels. Due Date works from whichever date you have: a last period, conception, an IVF transfer or an ultrasound.
Frequently asked questions
Is any of this medical advice?
No. These are population-level estimates from documented formulas, useful for orientation and for a conversation with a clinician — not a diagnosis and not a substitute for one.
How accurate is an estimated due date?
It is a statistical midpoint: only a small minority of babies arrive on their exact estimated date. Ultrasound dating by a clinician is more precise, and the page says so.
Why does BMI not distinguish muscle from fat?
Because it cannot: it is a ratio of weight to height squared and knows nothing about body composition. That is a real limitation of the measure itself, stated on the page rather than hidden.