Health calculators
Body metrics. Not medical advice.
- BMI Calculator: Body Mass Index and Healthy Weight Range
Body Mass Index from height and weight, with the CDC/WHO adult categories, the Asia-Pacific cut-offs and the healthy weight range for your height.
- BMR Calculator (Mifflin-St Jeor and Harris-Benedict)
Basal metabolic rate from weight, height, age and sex, by the two standard formulas, working shown.
- TDEE Calculator (Total Daily Energy Expenditure from BMR)
Total daily energy expenditure from your BMR and activity level, with the working, all five levels side by side and the FAO/WHO activity bands.
- Body Fat Calculator (US Navy Tape Method)
Body fat percentage from a tape measure by the US Navy equations, with the working in inches, the ACE category, and fat and lean mass.
- Pregnancy Due Date Calculator (LMP, Conception or IVF)
Due date from your last period, conception date or IVF transfer, with how far along you are, the trimesters and the term dates week by week.
- Ideal Weight Calculator (Devine, Robinson, Miller, Hamwi)
Ideal body weight by the four clinical formulas — Devine, Robinson, Miller and Hamwi — side by side, with the BMI 18.5–24.9 healthy range for your height.
- Macro Calculator (Protein, Carbs and Fat in Grams)
Protein, carb and fat grams from your calories and percentages, per day and per meal, checked against the National Academies' AMDR ranges.
- Calorie Deficit Calculator (Weekly Loss and the 3,500-Calorie Rule)
Daily calorie deficit from TDEE and target intake, the early weekly loss by the 3,500-calories-a-pound (7,700 kcal/kg) rule, and what the NIH weight model says happens over a year.
- Ovulation Calculator (Fertile Window and Next Period)
Ovulation day and the six-day fertile window from your last period and cycle length, with the next period, the test date and the next three cycles.
- Heart Rate Zones Calculator (Max HR, Karvonen & Target Heart Rate)
Five training zones from your age, with your resting heart rate (Karvonen) if you know it.
- Water Intake Calculator (How Much Water Should I Drink?)
Daily water to drink from the National Academies' Adequate Intakes for men, women, pregnancy and breastfeeding, plus an allowance for exercise.
- Waist-to-Hip Ratio Calculator (WHO Cut-offs)
Waist-to-hip ratio against the WHO cut-offs, plus your waist circumference against its own lines.
- Running Pace Calculator (Pace, Finish Time and Splits)
Pace per km and per mile from distance and time, or finish time from pace, for 5K, 10K, half and full marathon — with splits and Riegel race predictions.
- Protein Intake Calculator (Grams per Day by Body Weight)
Daily protein in grams from body weight, from the 0.8 g/kg (0.36 g/lb) RDA to the ISSN's 1.4–2.0 g/kg (0.64–0.91 g/lb) for exercise, with per-meal grams and the share of your calories.
- Sleep Cycle Calculator (Best Time to Wake Up or Go to Bed)
Wake-up times from your bedtime, or bedtimes from your alarm, in whole 90-minute sleep cycles.
- A1C to Glucose Calculator (eAG, mmol/L and mmol/mol)
HbA1c to estimated average glucose and back, in mg/dL, mmol/L and IFCC mmol/mol.
- VO₂ Max Calculator (Cooper Run, Rockport Walk or Resting Heart Rate)
Estimate VO₂ max from a Cooper 12-minute run, a Rockport one-mile walk or your resting heart rate, with each published formula and the working shown.
- Lean Body Mass Calculator (Boer, Hume or Your Body Fat %)
Lean mass and estimated fat from weight, height and sex, or from a known body fat %.
- Maintenance Calorie Calculator (Calories to Maintain Weight)
Calories to keep your weight steady, from sex, age, weight, height and activity by Mifflin-St Jeor, with both steps of the working and all five activity levels.
- Peptide Reconstitution Calculator (Dose to Syringe Units)
Vial strength and water to a volume on the syringe.