Fitness & Health Calculators
Body metrics and nutrition targets based on formulas used by US clinicians and dietitians.
BMI Calculator
Free BMI calculator using imperial or metric units.
Fitness & Health
Calorie Calculator
Find out how many calories you need per day to maintain, lose, or gain weight.
Fitness & Health
Body Fat Calculator
Estimate body fat percentage with the US Navy tape method or BMI formula.
Fitness & Health
BMR Calculator
Basal metabolic rate by three formulas: Mifflin-St Jeor, revised Harris-Benedict, and Katch-McArdle.
Fitness & Health
Macro Calculator
Turn calorie targets into daily protein, carb, and fat grams using popular macro splits.
Fitness & Health
Ideal Weight Calculator
Compare five ideal body weight formulas plus your healthy BMI weight range for any height.
Fitness & Health
Pregnancy Calculator
Track pregnancy week from LMP, see trimester progress, and confirm the estimated due date.
Fitness & Health
Pregnancy Weight Gain Calculator
Recommended pregnancy weight gain ranges by pre-pregnancy BMI and current week (IOM/NAM guidelines).
Fitness & Health
Pregnancy Conception Calculator
Estimate when conception occurred from the due date or last menstrual period, including IVF transfer dates.
Fitness & Health
Due Date Calculator
Predict your due date from the first day of your last period (adjusted for cycle length) or from conception.
Fitness & Health
Pace Calculator
Solve pace, time, or distance, and predict race times across 5k to marathon using Riegel's formula.
Fitness & Health
Army Body Fat Calculator
Compute body fat with the official DoD circumference tape method and check against Army standards.
Fitness & Health
Carbohydrate Calculator
Daily carbohydrate gram targets based on calorie intake and diet approach, from balanced to keto.
Fitness & Health
Lean Body Mass Calculator
Estimate lean body mass from height, weight, and sex using the Boer equation, or directly from body fat %.
Fitness & Health
Healthy Weight Calculator
See the exact weight range classified healthy (BMI 18.
Fitness & Health
Calories Burned Calculator
Calories burned by activity, duration, and body weight using standard MET values.
Fitness & Health
One Rep Max Calculator
Estimate your one rep max from any weight × reps set, with percentage training tables.
Fitness & Health
Target Heart Rate Calculator
Training heart-rate zones via the Karvonen method using age and resting heart rate.
Fitness & Health
Protein Calculator
Daily protein targets in grams per kg based on activity level, goals, and life stage.
Fitness & Health
Fat Intake Calculator
Daily dietary fat targets in grams based on calories, within the 20–35% AMDR range.
Fitness & Health
TDEE Calculator
Total daily energy expenditure from Mifflin-St Jeor BMR scaled by activity, with metric or imperial inputs.
Fitness & Health
Ovulation Calculator
Predict ovulation dates and fertile windows from cycle start and length over coming months.
Fitness & Health
Conception Calculator
Estimate which intercourse date likely conceived, given a due date or birth date.
Fitness & Health
Period Calculator
Predict upcoming periods from cycle history: start dates, duration, and fertile-day markers.
Fitness & Health
GFR Calculator
Estimate kidney filtration rate (eGFR) with the race-free CKD-EPI 2021 creatinine equation and CKD staging.
Fitness & Health
Body Type Calculator
Classify body shape (hourglass, pear, apple, rectangle) from bust, waist, and hip measurements.
Fitness & Health
Body Surface Area Calculator
Body surface area by five clinical formulas, used for dosing and cardiac indices.
Fitness & Health
BAC Calculator
Estimate blood alcohol content over time with the Widmark formula.
Fitness & Health
Anorexic BMI Calculator
BMI assessed against eating-disorder risk thresholds, with supportive resources attached.
Fitness & Health
Weight Watchers Points Calculator
Classic Weight Watchers Points formula from calories, fat, and fiber per serving.
Fitness & Health
Overweight Calculator
Quantify excess weight above the BMI-25 boundary (and obesity threshold) for your height.
Fitness & Health
About these calculators
Health tracking starts with honest baselines. These calculators use the same equations clinicians and dietitians use: the Mifflin-St Jeor formula for basal metabolic rate (validated as the most accurate general-population BMR equation) and the standard adult BMI categories published by the CDC.
Results update instantly in either imperial or metric units. As always, these numbers are screening tools — discuss any health changes with your doctor.