Health & Fitness Calculators
31 free calculators for BMI, calorie, pregnancy, and fitness calculations
Browse by Category
Body Metrics
13 calculators
Fitness & Exercise
8 calculators
Nutrition & Diet
7 calculators
Medical & Clinical
7 calculators
Lifestyle & Wellness
31 calculators
Pregnancy & Baby
6 calculators
About Our Health Calculators
Disclaimer: All health calculators use standard reference formulas and are for informational purposes only. They do not constitute medical advice. Consult a doctor or registered dietitian before making changes to your diet, exercise routine, or health plan.
Body Metrics
Body metrics calculators give you a baseline picture of your physical health. The BMI calculator divides your weight in kilograms by your height in meters squared. A BMI between 18.5 and 24.9 is considered healthy by most clinical guidelines, though it does not account for muscle mass or body composition. Pair BMI results with the body fat calculator and ideal weight calculator to get a more complete view.
Calories and Nutrition
The BMR calculator shows how many calories your body burns at rest. Multiply that by an activity factor to get your TDEE (Total Daily Energy Expenditure), the number you need to maintain your current weight. Eat below TDEE to lose weight, above it to gain. Use the TDEE calculator to get your daily number in one step. The macro calculator then splits your daily calories into protein, carbs, and fat targets based on your goal. These numbers work as a starting point; adjust based on how your body responds over a few weeks.
Pregnancy and Ovulation
The due date calculator estimates your delivery date based on the first day of your last menstrual period (LMP). Most pregnancies last around 40 weeks from that date. The ovulation calculator identifies your fertile window by tracking your cycle length. These tools are useful for planning, but cycle lengths vary; a healthcare provider can give you a more precise timeline with an ultrasound.
Frequently Asked Questions
How accurate is the BMI calculator?
BMI is accurate as a population-level screening tool, but it has limits at the individual level. It does not distinguish fat from muscle, so athletes and older adults may get misleading results. Use it as one data point alongside waist measurement and body fat percentage, and discuss the result with your doctor.
What is the difference between BMR and TDEE?
BMR is the calories your body needs to function at complete rest: breathing, circulation, cell repair. TDEE adds in your daily activity. If you want to manage your weight, TDEE is the number you work with. BMR alone tells you the floor, not your real daily need.
Can I use the calorie calculator to plan a diet?
Yes, as a starting point. The calorie calculator and macro calculator give you targets based on standard formulas. Track your intake for a few weeks and adjust if your weight is not moving in the right direction. Individual metabolism varies, so the numbers are a guide, not a guarantee.
Do these calculators work for children?
Most calculators on this page are built for adults. BMI interpretation for children uses age- and sex-specific percentiles, which is different from adult thresholds. For children and teenagers, use a pediatric BMI calculator and consult a pediatrician for guidance.