How do you calculate BMI?

BMI (Body Mass Index) is calculated by dividing your weight in kilograms by your height in meters squared: BMI = weight(kg) / height(m)². For example, a person who is 1.75 m tall and weighs 70 kg has a BMI of 70 / (1.75 × 1.75) = 22.9, which falls in the normal range (18.5–24.9).

What is a normal blood sugar level?

A normal fasting blood sugar level is 70–100 mg/dL (3.9–5.6 mmol/L). Prediabetes is indicated by fasting levels of 100–125 mg/dL (5.6–6.9 mmol/L). A fasting level of 126 mg/dL (7.0 mmol/L) or higher on two separate tests indicates diabetes. After eating, blood sugar normally stays below 140 mg/dL (7.8 mmol/L).

Health & Body Calculators

Calculate BMI, convert blood sugar units, and estimate daily calorie needs — all in one place.

Height

Weight

Your BMI

24.2

Normal

< 18.5Underweight

18.5 – 24.9Normal

25 – 29.9Overweight

30+Obese

Understanding BMI Categories

Body Mass Index (BMI) is a screening tool that estimates body fat based on height and weight. It applies to adult men and women aged 20 and older. While BMI does not measure body fat directly, research shows it correlates with more direct measures of body fat like skinfold thickness and dual-energy X-ray absorptiometry (DEXA).

Underweight (BMI < 18.5) — May indicate malnutrition, an eating disorder, or other health issues. Consult a healthcare provider.
Normal weight (BMI 18.5–24.9) — Associated with the lowest health risks from weight-related conditions.
Overweight (BMI 25–29.9) — May increase risk for cardiovascular disease, type 2 diabetes, and high blood pressure.
Obese (BMI 30+) — Significantly higher risk for multiple chronic conditions. Further subdivided into Class I (30–34.9), Class II (35–39.9), and Class III (40+).

BMI has limitations — it does not account for muscle mass, bone density, age, sex, or ethnic differences. Athletes with high muscle mass may have a high BMI without excess body fat. Always discuss your results with a healthcare professional.

BMI Formula

Metric: BMI = weight (kg) ÷ height (m)²

Imperial: BMI = [weight (lbs) ÷ height (in)²] × 703

Blood Sugar Units Explained

Blood glucose (blood sugar) is measured in two different units depending on your country. The United States uses mg/dL (milligrams per deciliter), while most of Europe, Canada, and Australia use mmol/L (millimoles per liter).

The conversion factor is straightforward: 1 mmol/L = 18.018 mg/dL. To convert mg/dL to mmol/L, divide by 18.018. To convert mmol/L to mg/dL, multiply by 18.018.

Monitoring blood sugar is essential for managing diabetes and prediabetes. Regular testing helps track how food, exercise, and medication affect glucose levels. An A1C test measures average blood sugar over 2-3 months — a normal A1C is below 5.7%, prediabetes is 5.7–6.4%, and diabetes is 6.5% or higher.

Quick Reference: Blood Sugar Ranges

Status	mg/dL	mmol/L
Normal (fasting)	70 – 100	3.9 – 5.6
Prediabetes	100 – 125	5.6 – 6.9
Diabetes	≥ 126	≥ 7.0
After meals (normal)	< 140	< 7.8
Hypoglycemia	< 70	< 3.9

What Is Basal Metabolic Rate (BMR)?

Your Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic life-sustaining functions at rest — breathing, circulation, cell production, and nutrient processing. It typically accounts for 60–75% of your total daily energy expenditure.

This calculator uses the Mifflin-St Jeor equation, which research has shown to be the most accurate formula for estimating BMR in most people. The equations are:

Male: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
Female: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161

To estimate your Total Daily Energy Expenditure (TDEE), multiply your BMR by an activity factor. Sedentary individuals multiply by 1.2, while very active people multiply by 1.725 or more. TDEE helps determine how many calories you need to maintain, lose, or gain weight.