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BMI Calculator

BMI (Body Mass Index) is a ratio of weight to height squared, used as a population-level screening tool for weight categories. Enter your height and weight below for your BMI, category, and healthy weight range, then see what BMI cannot: your actual body composition.

Reviewed by Andrew Menechian, Head of Fitness, FitCommit

Calculate Your BMI

Enter your height and weight for your BMI, category, and healthy weight range.

Your Stats

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in

Your BMI: 25.8 (Overweight)

A BMI of 25.8 falls in the overweight range (25 to 29.9). Modest reductions in weight through diet and exercise can meaningfully improve health outcomes.

Healthy weight range for your height: 122 to 164 lbs. That is about 6 lbs above the top of the range. BMI does not distinguish muscle from fat. FitCommit scans your body composition so you track what BMI cannot see.

Scan my body composition

BMI Category Reference

The World Health Organization (WHO) defines these BMI categories. Note that BMI is a screening tool, not a diagnostic measure. Body fat percentage, waist circumference, and other metabolic markers provide a more complete picture.

BMI RangeCategoryHealth Implication
Below 18.5UnderweightMay indicate nutritional deficiency or illness
18.5 to 24.9NormalAssociated with lowest health risk in population studies
25.0 to 29.9OverweightModestly elevated risk; often reversible with lifestyle changes
30.0 to 34.9Obese Class IElevated risk of cardiovascular disease and type 2 diabetes
35.0 to 39.9Obese Class IIHigh risk; medical evaluation recommended
40.0 and aboveObese Class IIIVery high risk; comprehensive medical intervention advised

Healthy Weight Range by Height

Healthy BMI (18.5 to 24.9) translates to these weight ranges depending on height.

HeightLow (BMI 18.5)High (BMI 24.9)Range
4'10"89 lbs119 lbs30 lbs
4'11"92 lbs123 lbs31 lbs
5'0"95 lbs127 lbs32 lbs
5'1"98 lbs132 lbs34 lbs
5'2"101 lbs136 lbs35 lbs
5'3"104 lbs141 lbs37 lbs
5'4"108 lbs145 lbs37 lbs
5'5"111 lbs150 lbs39 lbs
5'6"115 lbs154 lbs39 lbs
5'7"118 lbs159 lbs41 lbs
5'8"122 lbs164 lbs42 lbs
5'9"125 lbs169 lbs44 lbs
5'10"129 lbs174 lbs45 lbs
5'11"133 lbs179 lbs46 lbs
6'0"136 lbs184 lbs48 lbs
6'1"140 lbs189 lbs49 lbs
6'2"144 lbs194 lbs50 lbs
6'3"148 lbs199 lbs51 lbs
6'4"152 lbs205 lbs53 lbs
6'5"156 lbs210 lbs54 lbs
6'6"160 lbs215 lbs55 lbs

How BMI Is Calculated

BMI uses the following formula for imperial measurements:

BMI = (weight in lbs / height in inches squared) x 703

Example: A person who is 5'10" (70 inches) and weighs 180 lbs has a BMI of 25.8.

BMI Limitations

BMI does not distinguish between muscle and fat. A muscular athlete may have a high BMI while having low body fat. Always consider body composition alongside BMI.

When BMI Is Useful

BMI is a quick, cost-free screening tool suitable for tracking population health trends and identifying individuals who may benefit from further evaluation.

Where BMI Gets It Wrong

BMI was invented in the 1830s by a Belgian astronomer studying population averages, and that is still what it is best at: describing groups, not individuals. The formula sees only total weight and height. It has no idea whether the weight is muscle, fat, or bone, and that blind spot produces predictable failures.

It misreads muscular people in one direction: most serious lifters and many athletes are classified overweight or even obese while carrying athletic levels of body fat. It misreads under-muscled people in the other: a person can sit comfortably in the normal BMI range while carrying enough body fat and little enough muscle to face genuine metabolic risk, a pattern researchers call normal-weight obesity. It also drifts with age, because adults lose muscle over the decades while BMI keeps reading the total as if nothing changed. Two people with the same 24.5 BMI can be a lean recreational athlete and an under-muscled person with elevated visceral fat, and BMI hands them the same green checkmark.

None of this makes BMI useless. It is free, instant, and works as a first screen. It just cannot answer the question you are probably actually asking, which is how much of your body is fat.

BMI vs Body Fat Percentage: Which Should You Track?

Body fat percentage answers the question directly: it separates fat mass from lean mass, which is the distinction that drives both health risk and how you look. It is why a 200 lb lifter and a 200 lb sedentary man with the same 28.7 BMI have completely different health outlooks, and why we treat body fat percentage as the primary metric across this site and in the FitCommit app.

Tracking is where the difference compounds. Recomposition, losing fat while gaining muscle, can leave your weight and BMI unchanged for months while your body visibly transforms. BMI reports that as no progress. Body fat percentage reports what actually happened.

Practical rule: use BMI once as a rough screen, then switch to body fat percentage for anything involving a goal. You can estimate it free with our Navy-method body fat calculator or see what each level looks like in the body fat percentage guide.

What to Do at Each BMI Range

Under 18.5: the priority is usually gaining lean mass, not just weight. A moderate calorie surplus with resistance training and adequate protein builds muscle rather than fat. If weight loss was unintentional, see a physician first.

18.5 to 24.9: weight is not your signal here; composition is. Check body fat percentage to rule out the normal-weight-obesity pattern, then train for the body you want. Many people in this range benefit more from building muscle than from any change on the scale.

25 to 29.9: first verify the number means what it claims: if you lift regularly, your body fat percentage may already be fine. If it is genuinely elevated fat, a moderate deficit of 300 to 500 calories with high protein and strength training moves most people back under 25 within months while keeping the muscle.

30 and above: here BMI and body fat nearly always agree, and the health payoff for acting is at its largest. A 5 to 10% reduction in body weight measurably improves blood pressure, insulin sensitivity, and energy. Start with our calorie deficit calculator and build the plan around protein, steps, and three training days a week.

BMI Questions, Answered

Is BMI accurate?

BMI is accurate at what it was designed for: screening large populations by weight relative to height. It is unreliable for individuals because it cannot tell fat from muscle. A 5'10" man at 200 lbs has a BMI of 28.7 whether he is a lean lifter at 12% body fat or sedentary at 30%. For an individual decision, body fat percentage tells you what BMI cannot.

Why is my BMI high if I am muscular?

Muscle is denser than fat, so muscular people carry more weight per inch of height, and BMI reads all of that weight the same way. This is the best-known failure of BMI: it classifies many strength athletes as overweight or obese while their body fat sits in the athletic range. If you train seriously, measure body fat percentage instead of BMI.

What is a good BMI for my age?

The WHO healthy range of 18.5 to 24.9 applies to all adults, but the evidence in adults over 65 favors the higher end of that range and slightly above it, because low weight in older adults often reflects muscle loss. At every age the more useful question is body composition: how much of your weight is lean mass versus fat.

What is better than BMI?

For individuals, body fat percentage is the more informative metric because it separates fat from lean mass, which is the distinction that actually drives health risk and appearance. Waist-to-height ratio is a good second check for where fat sits. BMI remains useful as a fast, free first screen.

Can I have a normal BMI and too much body fat?

Yes. This pattern, sometimes called normal-weight obesity, describes people whose BMI sits in the healthy range while their body fat percentage is high and muscle mass is low. It carries real metabolic risk that BMI never flags, and it is one of the strongest reasons to measure body composition directly rather than relying on the scale and a height chart.

How do I lower my BMI?

Since BMI only tracks weight, anything that reduces weight lowers it, including losing muscle, which you do not want. The better goal is lowering body fat while keeping lean mass: a moderate calorie deficit, high protein intake, and resistance training. Our TDEE and calorie deficit calculators give you the exact numbers.

Related Resources

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