Online Health Calculators
Filter health calculators by result
Filter by the result you want: view BMI, body-fat and body-measurement references, plan target body fat and weight-loss time, set daily energy and nutrition targets, or estimate caffeine, sugar, and water intake.
Common limitations
- These calculators are screening and reference tools, not medical assessments.
- A result is not a diagnosis and should not be used on its own to make a treatment decision.
- Formulas may not be suitable for children, pregnancy, or particular medical conditions; check the tool notes and seek professional guidance when needed.
Measurement & estimation
- Measurements and formulas have uncertainty, so an estimate should not be treated as an exact value.
- Small differences in an input or measurement method may change the result.
- Applicability varies by population and formula; review the selected calculator's method and limits.
Health calculator questions
Are these calculators medical diagnoses?
No. They provide screening or reference estimates, not diagnoses. Use a qualified professional for assessment or advice about a health concern.
Which calculator should I use?
Choose BMI for a height-and-weight screening reference, body-fat or ratio tools for measurement-based estimates, TDEE and nutrition tools for daily intake planning, and goal tools for planning scenarios. Read each tool's inputs and limits.
Why can different formulas give different results?
Different formulas use different inputs, constants, populations, and assumptions. They can therefore produce different estimates even when the same general goal is being considered.
When should I consult a professional?
Consult a qualified professional if you have symptoms, a medical condition, are pregnant, are using results to make a health decision, or are unsure how to interpret the result.
All Tools
14 tools available. Select one to open it here.
Macro Calculator
Calculate daily protein, fat, and carbohydrate targets from calories, weight, and your preferred allocation rule.
Carbohydrate Needs Calculator
Enter daily calories, weight, goal, training volume, and carbohydrate percentage to estimate daily carbohydrate grams, calories, and a reference range.
BMI Calculator
Calculate BMI, a healthy weight range, and adult screening categories from your height and weight.
Ideal Weight Calculator
Compare four classic ideal-weight formulas and the adult BMI reference range using your height and sex.
Body Fat Goal Calculator
Enter your current weight, body fat percentage, and daily calorie deficit to estimate your target weight, amount of fat you need to lose, and the time frame.
Waist-to-Hip Ratio Calculator
Enter sex, waist circumference, and hip circumference to calculate WHR and view common WHO adult reference cutoffs and measurement guidance.
Waist-to-Height Ratio Calculator
Enter waist circumference, height, and optional age to calculate WHtR, view a continuous adult reference band, and compare waist size with half your height.
Body Fat Calculator (U.S. Navy Method)
Estimate body fat percentage, fat mass, and lean mass from sex, height, weight, and body circumferences using the classic U.S. Navy method.
TDEE Calculator
Enter sex, age, height, weight, and activity level to estimate BMR, TDEE, and a maintenance-calorie range, with steps and training minutes to check the activity factor.
Calorie Deficit Calculator
Enter TDEE, select fat loss, maintenance or muscle gain mode, and instantly calculate target calories, daily difference, theoretical weekly change and planning range.
Caffeine Intake Calculator
Enter drink servings, volume, and caffeine per serving to estimate daily caffeine, source shares, and an adult reference comparison.
Sugar Intake Calculator
Enter daily calories and sugar sources to calculate added sugar, free sugars, and their share of energy.
Weight loss time calculator
Enter your current weight, target weight, and weekly weight loss rate to estimate the weeks required, target date, and planning range.
Water Intake Calculator
Estimate a daily beverage range from your weight, activity and heat or sweating, while keeping the total-water Adequate Intake (AI) reference separate.