Health Calculators – Free Online Health & Fitness Tools

BMI Calculator

Body Mass Index — find out if your weight is healthy for your height.

Height — feet

Height — inches

Weight (lbs)

Your BMI

Underweight
<18.5 Normal
18.5–25 Overweight
25–30 Obese
>30

BMI is a screening tool, not a diagnostic measure. Consult a healthcare provider for a complete health assessment.

Daily Calorie Calculator

Find your daily calorie needs to maintain, lose, or gain weight using the Mifflin-St Jeor equation.

Gender

Male Female

Age

Weight (lbs)

Height — feet

Height — inches

Activity Level

Calories to Maintain Weight

Lose 0.5 lb/wk

Lose 1 lb/wk

Gain 0.5 lb/wk

Gain 1 lb/wk

These are estimates based on averages. Your actual needs may differ. Consult a registered dietitian for personalized guidance.

Body Fat % Calculator

Estimate body fat percentage using the U.S. Navy circumference method. All measurements in centimeters.

Gender

Male Female

Height (cm)

Weight (kg)

Neck circumference (cm)

Waist circumference (cm)

Hip circumference (cm) — females only

Estimated Body Fat

Fat Mass (kg)

Lean Mass (kg)

The Navy method has a margin of error of ±3–4%. DEXA scan is the gold standard for precise body composition analysis.

Pregnancy Due Date Calculator

Calculate your estimated due date using Naegele's rule based on your last menstrual period.

First day of last menstrual period

Average cycle length (days)

Estimated Due Date

Est. Conception

Weeks Pregnant

Days Until Due

Trimester

Only about 5% of babies are born on their due date. This is an estimate. Always follow your healthcare provider's guidance.

Ovulation Calculator

Identify your fertile window and most likely ovulation date to help you plan or prevent pregnancy.

First day of last menstrual period

Average cycle length (days)

Estimated Ovulation Date

Fertile Window Starts

Fertile Window Ends

Next Period Est.

Ovulation dates are estimates based on average cycle patterns. Actual ovulation varies. This tool is not a reliable method of contraception.

TDEE Calculator

Total Daily Energy Expenditure — your complete daily calorie burn accounting for activity level, with macro breakdown.

Gender

Male Female

Age

Weight (lbs)

Height — feet

Height — inches

Activity Level

Total Daily Energy Expenditure

Basal Metabolic Rate

Protein (g)

Carbs (g)

Fats (g)

Macros shown at a 30/40/30 protein/carb/fat split. Individual needs vary — adjust based on your goals and consult a dietitian.

Blood Pressure Checker

Enter your blood pressure reading to see your category according to the American Heart Association scale.

Systolic pressure (top number) mmHg

Diastolic pressure (bottom number) mmHg

Your Blood Pressure

Normal

<120 / <80

Elevated

120–129 / <80

High — Stage 1

130–139 / 80–89

High — Stage 2

140–179 / 90–119

Crisis

>180 / >120

This tool is for informational purposes only. Always consult a doctor for blood pressure diagnosis, monitoring, and management.

Sleep Calculator

Find the optimal times to wake up or go to sleep based on 90-minute sleep cycles and average sleep-onset latency.

Wake-up time

We'll calculate the ideal bedtimes so you wake up between sleep cycles.

Suggested Bedtimes

Each cycle = 90 min. Average time to fall asleep = 14 min. Wake between cycles for best results.

Adults typically need 7–9 hours (5–6 complete cycles). These are estimates — your individual sleep needs may vary.