Browse all 24 calculators in this category.
24 health and fitness calculators covering BMI, body composition, calories and macros, weight goals, exercise, pregnancy, and sleep.
Take control of your health with 24 calculators. Estimate BMI, body fat and lean mass; plan nutrition with calorie, protein, macro, BMR and TDEE tools; set weight and fitness goals; and explore pregnancy dates, ovulation and sleep cycles. Results are estimates, not medical advice.
Explore practical examples and the reasoning behind these calculations.
Learn what basal metabolic rate (BMR) actually measures, how the Mifflin-St Jeor and Harris-Benedict formulas differ, what TDEE is, and why eating at BMR is one of the most common diet mistakes.
Understand what macronutrients are, why they matter beyond total calories, how to set protein, carb, and fat targets for cutting or bulking, and practical strategies for hitting your macros every day.
Learn the relationship between pace, speed, and distance, how to use the Riegel formula to predict race times, what negative splits are, and how to structure training pace zones for a 5K, half marathon, or marathon.
Learn how gestational age is calculated from LMP vs. conception, how Naegele's rule works, key milestones in each trimester, how IVF due dates differ, and what 'full term' really means.
Understand what happens during each of the 4 sleep stages, why waking mid-cycle causes grogginess, how 7.5 hours (5 cycles) can feel better than 8 hours, and evidence-based tips for optimizing your sleep timing.