5'9 Is the Middle for U.S. Men: What Height and Weight Say Next

Height percentile, lean body mass and body surface area from one height and weight: 5'10 and 180 lb is 63rd percentile, 126.9-138.5 lb lean, 2.01 m2.

What do your height and weight actually say about you?

"Is 5'9 tall for a man?" Type that into a search box and it offers to finish the same question for every height from 5'4 to 6'5. The short answer for that one: no, it is the middle. Among U.S. men aged 20 and over the measured median is 5 ft 9.1 in, so 5 ft 9 in sits at about the 49th percentile.

The longer answer is that a height and a weight, the two numbers on almost every medical form, quietly hold three different facts about a body. Where you stand in the adult population. How much of your weight is not fat. And how much skin covers you, which is the figure doctors reach for when a dose or a measurement has to be scaled to body size. This article runs one ordinary body through all three, then changes one thing at a time to see which number moves.

The body: a man, 5 ft 10 in and 180 lb. Nothing special about him, which is the point.

Where do the three numbers come from?

Each one is built differently, and that matters more than the arithmetic. The height percentile is a lookup against people who were actually measured. The other two are formulas, curves fitted to small groups decades apart, and they disagree with each other in ways worth seeing.

Number	Built from	Source	For 5 ft 10 in, 180 lb, man
Height percentile	height, sex, age group	measured heights of U.S. adults, NCHS tables	63rd
Lean body mass	height, weight, sex	four equations: Boer, James, Hume, Janmahasatian	126.9 to 138.5 lb
Body surface area	height, weight	five formulas, Mosteller to Boyd	2.01 m²

Read the table from left to right and something stands out: only one of the three numbers knows how old you are, and only two of them know whether you are a man or a woman. Keep that in mind for the what-ifs below.

The height percentile

The Adult Height Percentile Calculator places a height among U.S. adults using the anthropometric reference tables of the National Center for Health Statistics. Those tables come from the National Health and Nutrition Examination Survey, where staff measured 5,092 men and 5,510 women standing against a wall-mounted stadiometer. The report prints nine cut points per group, from the 5th to the 95th percentile, and the calculator draws a straight line between neighboring points. Our man at 5 ft 10 in is 177.8 cm. The median for men 20 and over is 175.4 cm and the 75th percentile is 180.2 cm, so he lands at the 63rd, 0.9 in above the middle.

Age changes the answer more than most people expect. The screenshot below is a slightly taller example, 5 ft 11 in, compared with men aged 30 to 39: 69th percentile. The same 5 ft 11 in is the 76th among all men 20 and over and the 91st among men 80 and over, because the older groups in the survey are shorter.

Adult height percentile calculator: a man of 5 ft 11 in aged 30-39 at the 69th percentile, with the same height in every age group

The lean body mass

Lean body mass is everything that is not fat: muscle, bone, organs, water. The Lean Body Mass Calculator estimates it from height, weight and sex with four published equations, and it shows all four on purpose:

Equation	Lean mass	Share of 180 lb
Boer	135.6 lb	75%
James	138.5 lb	77%
Hume	126.9 lb	71%
Janmahasatian	136.1 lb	76%

Same man, four answers, 11.6 lb apart. None of them is a typo. Each equation was fitted to a different group of people, and in a comparison against DXA scans of 1,558 adults aged 60 to 65, Puri and colleagues reported 95% limits of agreement between 11.3 and 16.9 kg for three of them. So the honest output is a range, 126.9 to 138.5 lb, with its middle at 132.7 lb, about 74% of his weight.

If he has a measured body fat percentage, the arithmetic gets simpler and more personal. At 20% body fat, 180 lb times 0.80 is 144.0 lb of lean mass, which is 11.3 lb above the middle of the equation range and outside it altogether. The equations only know height and weight, so they describe an average body of that size; a man who trains carries more lean mass than they can see.

Lean body mass calculator: 180 lb, 5 ft 10 in, 20% body fat gives 144.0 lb against an equation range of 126.9 to 138.5 lb

The body surface area

Body surface area is the area of skin, in square meters. It sounds like trivia until you learn that chemotherapy doses, kidney function figures and transplant measurements are often scaled to it. The Body Surface Area Calculator runs five formulas. For our man the Mosteller formula, the square root of height in cm times weight in kg over 3600, gives 2.01 m², or 21.6 square feet. The other four land between 2.00 and 2.02. For an ordinary adult build the formulas agree closely; they part company for babies and for very short or very heavy people, as Redlarski and colleagues showed when they compared 25 of them.

Body surface area calculator: 70 kg and 170 cm give 1.82 m2 by Mosteller, with all five formulas between 1.81 and 1.83 m2

The screenshot uses a metric example, 70 kg and 170 cm: 1.82 m², with all five formulas between 1.81 and 1.83. None of this is for working out a dose; that is a clinician's job with a formula their protocol names.

What if one thing changes?

Now the useful part. Keep the body and change a single input.

What if the same height and weight belong to a woman?

A woman of 5 ft 10 in is above the 95th percentile of U.S. women 20 and over; the median woman is 5 ft 3.5 in, 6.5 in shorter. Her lean mass range at 180 lb drops to 110.6 to 124.3 lb, because every equation has a separate, lower set of coefficients for women. Her body surface area? Exactly the same 2.01 m². The five BSA formulas take height and weight only. Of the three numbers, it is the one that does not care about sex at all.

What if he gains 30 pounds?

At 210 lb his height percentile does not move, obviously. The lean mass range climbs to 136.8 to 150.0 lb, so the middle rises by 10.7 lb for 30 lb of extra weight: the equations count about two thirds of new weight as fat. Body surface area rises to 2.17 m², about 8% more skin for about 17% more weight. Surface grows more slowly than mass; that is geometry, not biology.

What if he loses 30 pounds instead?

At 150 lb the range narrows to 117.1 to 123.7 lb, middle 120.4 lb, now about 80% of his weight. Notice the spread between equations shrank from 11.6 lb to 6.6 lb. The formulas disagree least for lean, average builds and most for heavier ones. BSA falls to 1.83 m².

What if he is 6 ft 3 in at the same 180 lb?

Five more inches put him above the 95th percentile, past the edge of the published table. At the same weight his lean mass range moves up to 136.4 to 146.2 lb, because every equation adds lean mass with height, and his BSA rises to 2.08 m². A taller, slimmer frame of the same weight carries more skin and, on paper, more lean tissue.

What if you compare with your own age group?

Height is the only one of the three that changes its verdict with age, and it changes a lot. The 5 ft 11 in from the screenshot runs from the 69th percentile at 30 to 39 to the 91st at 80 and over. The survey cannot say how much of that gap is height lost over a lifetime and how much is a later birth year, so the fair comparison is with your own ten-year group.

What if the body is a newborn?

A baby of 3.5 kg and 50 cm has a body surface area of about 0.22 m². Per kilogram that is 630 cm² of skin, against 246 cm² for our 180 lb man. Small bodies have far more surface for their weight. Here the five formulas also disagree by 12%, the widest gap in this article.

The same five bodies, side by side

Here is every scenario in one table. The last row is the verdict on each number: what it responds to.

Body	Height percentile (20 and over)	Lean mass range	BSA, Mosteller
Man, 5 ft 10 in, 180 lb	63rd	126.9 to 138.5 lb	2.01 m²
Woman, 5 ft 10 in, 180 lb	above the 95th	110.6 to 124.3 lb	2.01 m²
Man, 5 ft 10 in, 210 lb	63rd	136.8 to 150.0 lb	2.17 m²
Man, 5 ft 10 in, 150 lb	63rd	117.1 to 123.7 lb	1.83 m²
Man, 6 ft 3 in, 180 lb	above the 95th	136.4 to 146.2 lb	2.08 m²
Best single read	only height matters	weight moves it most	blind to sex

So which number is worth knowing?

For curiosity, the height percentile, because it is the only one built on people who were actually measured, and it answers the question most of us type. For training or nutrition, lean body mass, but read it as a range unless you have a measured body fat percentage; the equations cannot see muscle. Body surface area is the specialist's number. It is the most stable of the three across formulas for ordinary adults, it ignores sex, and its real job is in a clinic, not on a scale.

And 5 ft 9 in? Still the middle. Average is not short.

Tools discussed in this article

Adult Height Percentile Calculator - your height in feet and inches or centimeters as a percentile of U.S. men or women of your age group, from the measured NHANES tables.
Lean Body Mass Calculator - four published lean body mass equations side by side in pounds or kilograms, with a measured body fat percentage set against them.
Body Surface Area Calculator - body surface area in square meters and square feet by five formulas, from Mosteller to Boyd, with the spread between them.

Ready-made calculations from this article

Is this height tall for a man? 5'4, 5'5, 5'6, 5'7, 5'8, 5'9, 5'10, 5'11, 6'0, 6'1, 6'2, 6'3

Is this height tall for a woman? 4'10, 4'11, 5'0, 5'1, 5'2, 5'3, 5'4, 5'5, 5'6, 5'7, 5'8, 5'9