Track your body, diet and sleep: BMI, calories, TDEE, body fat, water intake and more. Free health calculators that work for everyone.
Body Mass Index with healthy-range category.
Basal metabolic rate — calories your body burns at rest.
Daily calorie needs for weight goals.
Total daily energy expenditure with cutting/bulking targets.
US Navy method estimate with visual gauge.
Healthy weight range from 4 medical formulas.
Daily water target based on weight and activity.
Best bedtimes and wake times by sleep cycles.
Pace, speed and race-time predictions.
Due date from last period with week-by-week info.
Fertile window and ovulation day predictor.
Next periods, fertile days and ovulation calendar.
Tracking health numbers helps you make better daily decisions: your BMI shows where your weight stands, the calorie calculator estimates what you burn, and the water-intake tool tells you how much to drink for your body weight. Sleep and pregnancy calculators turn confusing dates into clear answers in seconds.
All calculators are 100% free with no signup and run entirely in your browser, so your health data stays private on your device. They work on any phone or computer and give instant results — no waiting, no accounts, no limits.
People use these daily: checking BMI before starting a fitness plan, estimating calories for a diet, finding the fertile window when planning a family, or calculating a due date after a positive test. The numbers are estimates to guide you — always consult a doctor for medical decisions.
Health numbers answer different questions, and using the wrong one leads to wrong conclusions. This toolkit covers the full set — each calculator below maps to exactly one question about your body, so start from the question, not the tool.
Weight & energy: BMI (weight ÷ height²) screens weight categories — 18.5–24.9 is "normal" — but ignores muscle. BMR (Mifflin-St Jeor) is your at-rest calorie burn; TDEE multiplies it by activity level for your true daily target; the Calorie Calculator splits TDEE into lose/maintain/gain plans. Body Fat (Navy tape method) measures composition, which the scale can't. Ideal Weight gives a healthy range for your height. Water Intake (≈35 ml per kg of body weight) sets a hydration target. Sleep Calculator works backward from your alarm in 90-minute sleep cycles to find bedtimes that avoid mid-cycle waking. Running Pace converts time ÷ distance into training paces. Pregnancy Due Date adds 280 days to the last menstrual period (Naegele's rule); Ovulation estimates ~14 days before the next period; the Period Tracker predicts upcoming cycles.
Who benefits: anyone starting a fitness routine, setting weight goals, training for a run, tracking hydration or sleep, or expecting a baby — basically, anyone who wants numbers instead of guesses about their body.
Practical tips: check BMI monthly, recalculate TDEE whenever weight shifts ~5 kg, and re-measure body fat every 4–6 weeks — trends beat single readings every time. Limitation: these are screening estimates, not medical advice; for health decisions, diagnoses, or pregnancy care, always confirm with a qualified clinician.
Two numbers most people ignore: the waist-to-height ratio — keep your waist under half your height — predicts cardiovascular risk better than BMI in several large studies, because it captures visceral fat that BMI misses. A 175 cm person should aim for a waist under 87.5 cm. Second, resting heart rate trends: a gradual decline over months of training signals improving fitness; a sudden 5–10 bpm rise often precedes illness or overtraining by days. Pair these with the calculators here for a fuller picture: BMI for population screening, waist-to-height for fat distribution, body-fat % for composition, TDEE for energy balance. No single number tells the story — the combination, tracked quarterly, does. And the unglamorous truth behind every calculator on this page: consistent sleep, daily movement, and a modest calorie deficit outperform any optimization of the numbers themselves.
Yes — all health tools here are 100% free, no signup needed.
These are estimates for general guidance only, not medical advice. Consult a doctor for health decisions.
Yes. All calculations happen in your browser — nothing is uploaded or stored.
Start with the TDEE calculator to find your maintenance calories, then use the Calorie Calculator to set a deficit — typically around 500 kcal under maintenance for steady loss. Recheck monthly: as you lose weight your TDEE drops, so targets need regular updating.
BMI ignores muscle entirely, so athletes and regular lifters often score 'overweight' while being lean. Pair it with the Body Fat Calculator — low body fat plus high BMI means muscle, not excess fat, and that's a good problem to have.
They're estimates built on averages: due dates assume a 28-day cycle, and ovulation is placed ~14 days before the next period. Real cycles vary considerably — treat predictions as windows, and confirm anything important with a clinician.