Health & fitness calculators
Free health and fitness calculators for BMI, daily calorie needs, water intake, pregnancy due date, ideal weight, body fat percentage, and more.
My Time Calculators provides 70 free health and fitness calculators including BMI, calorie/TDEE, body fat, ideal weight, water intake, pregnancy due date, and heart rate. All are free, instant, and based on established medical formulas.
All health calculators (70)
BMI
Body mass index
Calorie / TDEE
Daily calorie needs
Water intake
Daily hydration goal
Pregnancy due date
Estimated delivery date
Sleep calculator
Best wake-up time
Ideal weight
Healthy weight range
Body fat %
Estimate body fat
Max heart rate
Exercise heart rate zones
Steps to calories
Activity to energy
Protein intake
Daily protein needs
Ovulation
Fertile window
Blood pressure
BP category check
BAC estimator
Blood alcohol content
Medication dose
Dose by body weight
Calories burned
Energy burned by activity
Macro calculator
Protein, carbs & fat split
One-rep max
Estimate your 1RM
Waist-to-hip ratio
Health risk indicator
BMR calculator
Basal metabolic rate
Lean body mass
Muscle vs fat mass
Body surface area
BSA for dosing
Waist-to-height ratio
Quick health screen
Smoking cost
Money & cigarettes saved
A1C to glucose
Average blood sugar
Pregnancy week
How far along you are
Resting heart rate zone
Fitness from resting HR
Calorie deficit
Time to reach goal weight
Water by activity
Hydration for your day
Child BMI
BMI for children & teens
Due date by conception
EDD from conception date
VO2 max
Cardio fitness estimate
Calories for goal
Cut, maintain or bulk
Frame size
Body frame from wrist
Race time predictor
Finish time at your pace
Fasting window
Intermittent fasting times
Quit smoking savings
Health & money over time
Target heart rate
Training zones by method
TDEE calculator
Daily energy expenditure
Period / cycle
Predict your next period
Pregnancy weight gain
Healthy gain by week
Wilks score
Powerlifting strength score
FFMI
Fat-free mass index
Running calories
Calories burned running
Walking calories
Calories burned walking
Cycling calories
Calories burned cycling
Swimming calories
Calories burned swimming
Exercise calories (MET)
Calories for any activity
Push-up test
Fitness rating by age
Plank test
Core strength rating
Grip strength
Rating by age and sex
Protein per meal
Optimal protein per sitting
Sugar intake
Daily added sugar limit
Fiber intake
Daily fiber target
Caffeine limit
Safe daily caffeine
Alcohol calories
Calories in your drinks
Sodium limit
Daily salt guidance
Glycemic load
GL of a food portion
Mean arterial pressure
MAP from blood pressure
Pulse pressure
Systolic minus diastolic
Goal weight by BMI
Weight for a target BMI
eGFR (kidney)
Kidney function estimate
Cholesterol ratio
Total-to-HDL ratio
Body surface (Mosteller)
BSA for dosing
Blood oxygen guide
Interpret SpO2 levels
Due date (LMP)
Due date from last period
Fertile window
Most fertile days
Baby weight percentile
Infant growth check
Baby feeding amount
Daily milk for infants
Sleep debt
Accumulated lost sleep
Life expectancy
Lifestyle-adjusted estimate
Why use our health calculators
Understanding your body starts with understanding the numbers. Our health calculators translate measurements like weight, height, and age into meaningful insights — your BMI category, daily calorie needs, hydration targets, or target heart-rate zones. Each tool is grounded in widely used clinical formulas such as Mifflin–St Jeor for metabolism and the WHO classifications for BMI.
Health information is most useful when it is personal. A generic "drink more water" becomes actionable when you see your specific daily target in millilitres. "Eat less" becomes a concrete calorie number you can plan meals around. These calculators give you a starting baseline — a reference point for conversations with your doctor, coach, or your own goals.
How to choose the right calculator
- Choose the calculator that fits what you want to understand — weight, nutrition, fitness, or wellness.
- Enter your measurements using metric units (kilograms, centimetres) where required.
- Read your result alongside the reference ranges so you know what is typical.
- Treat the output as a guide, and consult a healthcare professional for medical decisions.
Frequently asked questions
Are these health calculators medically accurate?
They use established formulas (Mifflin–St Jeor, US Navy body-fat method, WHO BMI categories). They provide reliable estimates but are not a substitute for professional medical assessment.
Should I rely on these instead of a doctor?
No. These tools are educational and give useful baselines, but a qualified healthcare provider should guide any medical, dietary, or treatment decisions.
Do they work for all ages and body types?
Most are designed for healthy adults. Measures like BMI are less accurate for athletes, pregnant people, children, and the elderly, so interpret results in context.
Is my health data stored?
No. All calculations happen in your browser. Nothing you enter is saved, sent, or shared.