Track your physical wellbeing with medically backed formulas.
Split your daily calories into grams of protein, carbs, and fat.
Estimate your recommended daily water intake based on weight, activity, and climate.
Calculate your Body Mass Index (BMI) and find out which weight category you fall into. See your healthy weight range based on your height. Includes both metric and imperial units.
Find your daily calorie needs and Total Daily Energy Expenditure (TDEE) based on your age, weight, height, and activity level. Set a weight loss or gain goal and get your target calorie intake. Uses the Mifflin-St Jeor formula.
Find your ideal body weight using 4 evidence-based medical formulas: Hamwi, Devine, Robinson, and Miller. See the healthy BMI weight range for your height. Results shown for both men and women.
Calculate your Total Daily Energy Expenditure and Basal Metabolic Rate based on age, weight, height, and activity level. Set a calorie goal for weight loss, maintenance, or gain.
Calculate your body fat percentage using the US Navy method with neck, waist, and hip measurements. Includes body fat categories for men and women and a visual body composition breakdown.
Calculate your estimated pregnancy due date by last menstrual period, conception date, or IVF transfer. See gestational age, trimester, and all key pregnancy milestones.
Estimate your fertile window, ovulation date, and next period from your cycle.
Find the best time to go to bed or wake up based on 90-minute sleep cycles.
Free BMR calculator. Find your basal metabolic rate using the Mifflin-St Jeor, Harris-Benedict, or Katch-McArdle formula.
calculators
Understanding your body starts with understanding the numbers behind it. Body Mass Index, daily calorie intake, and ideal weight are not just abstract metrics — they are practical tools that doctors and nutritionists use every day to guide health decisions. Our health calculators bring these clinical-grade measurements to your fingertips for free. Whether you want to lose weight, build muscle, maintain your current physique, or simply understand where you stand on the BMI scale, our tools give you a clear, data-driven starting point based on your unique height, weight, age, and activity level.
How it works
Using our health calculators takes less than a minute. Enter your basic body measurements — age, height, weight, and gender — along with your physical activity level. Our engine instantly applies peer-reviewed medical formulas to compute your BMI category, your daily calorie needs for maintenance, weight loss, or weight gain, and your ideal weight range across multiple scientific models. Every result updates in real time as you adjust any input, so you can explore different scenarios like increasing your exercise frequency or adjusting your target weight. When you are satisfied, download a clean PDF summary to share with your doctor or personal trainer.
Always free
Health awareness should not come with a price tag. CalcHere provides all health calculators completely free — no premium plans, no locked features, no mandatory sign-ups. We are funded through non-intrusive advertising that does not interfere with your experience. Whether you check your BMI once or use our calorie calculator daily, every tool and every feature is always available without restrictions.
Wellness tips
Track BMI Over Time
A single BMI reading is a snapshot. Track your BMI monthly to spot trends and adjust your diet or exercise plan accordingly.
Adjust Calories to Activity Level
Your calorie needs change with your activity. Use the calorie calculator to compare sedentary, moderate, and active lifestyles and find the intake that matches your goals.
Use Multiple Formulas
Our ideal weight calculator offers several formulas (Devine, Robinson, Miller, Hamwi). Compare them to get a realistic target range rather than a single number.
Combine With a Fitness Plan
Calculators give you the numbers; a balanced exercise and nutrition plan puts them into action. Use your results as a baseline to set achievable weekly targets.
Consult a Professional
Online calculators provide useful estimates, but they cannot replace personalised medical advice. Share your results with a doctor or dietitian for a tailored health plan.
Log Your Progress
Download your results as PDF and keep a weekly log. Tracking changes over time reveals trends that a single measurement cannot show and keeps you motivated.
Our health calculators follow published, widely used medical equations — the Mifflin-St Jeor equation for Basal Metabolic Rate (BMR), the WHO formula for BMI, and the Devine, Robinson, Miller, and Hamwi formulas for ideal weight. We cite each source so you can verify the science yourself; these are established public formulas, not a proprietary or professionally reviewed methodology.
Weight, height, age, and body composition are deeply personal data. We process all your inputs locally in your browser using client-side JavaScript. Nothing is transmitted to our servers, no cookies store your measurements, and no third-party analytics tools can access the health information you enter. You can use our calculators with complete confidence that your sensitive health data stays entirely on your device.
CalcHere is developed by an independent team committed to evidence-based health tools. We are not affiliated with any pharmaceutical company, supplement brand, or diet program. Our calculators use peer-reviewed formulas from published medical research — not proprietary algorithms designed to sell you a product. The formulas, their sources, and their limitations are fully transparent so you can verify the science behind every result.
Every health calculation can be downloaded as a clean PDF with a single click. The report includes your input measurements, all calculated results (BMI category, calorie targets, ideal weight range), and the formulas used. Bring it to your next doctor's appointment, share it with your personal trainer, or keep it as a baseline for tracking your progress over time. No registration, no email, no watermarks — just your data in a printable format.
BMI (Body Mass Index) is calculated by dividing your weight in kilograms by the square of your height in meters: BMI = kg / m². The World Health Organization classifies BMI into categories: below 18.5 is underweight, 18.5–24.9 is normal weight, 25–29.9 is overweight, and 30 or above is considered obese. While BMI is a useful and widely recognized screening tool, it does not directly measure body fat percentage or account for muscle mass, so athletes and very muscular individuals may get misleading results.
Both are formulas for estimating your Basal Metabolic Rate (BMR) — the number of calories your body burns at rest. The Mifflin-St Jeor equation, published in 1990 and validated in subsequent studies, is considered more accurate for modern populations because it was developed using a more diverse and representative sample. The original Harris-Benedict equation from 1919 (revised in 1984) tends to overestimate calorie needs by about 5%. Our calorie calculator defaults to Mifflin-St Jeor but lets you compare both for reference.
Ideal weight is a clinically estimated healthy weight range based on your height and gender. Rather than giving you a single target number, our calculator uses four established medical formulas — Devine (1974), Robinson (1983), Miller (1983), and Hamwi (1964) — to provide a realistic range. This approach is more practical because body composition, bone structure, and muscle mass vary significantly between individuals. The range gives you a healthy target zone to work toward rather than an arbitrary single number.
For general health monitoring, checking your BMI once a month is sufficient to spot any concerning trends. If you are actively on a weight loss or weight gain program, bi-weekly measurements can help you track progress and make timely adjustments to your diet or exercise plan. Keep in mind that daily weight fluctuations are normal due to water retention and meal timing, so measuring under consistent conditions (same time of day, same clothing) gives you the most reliable data.
Our calculators apply the same published formulas used in clinical and research settings, such as Mifflin-St Jeor and the WHO BMI classification. They are screening and estimation tools, not medical diagnoses. Individual factors like medical conditions, medications, pregnancy, or unusual body composition can affect the applicability of these general formulas. Always consult a qualified healthcare professional for personalized medical advice, especially before making significant changes to your diet or exercise routine.