Neck Size: How to Measure It and How Much It Grows

How to measure a neck

Almost every argument about neck size is really an argument about measurement technique, so start here.

Where. The narrowest point of the neck, which for most people sits just below the larynx. Some lifters measure at the widest point instead, which produces a bigger number and is not wrong — it is just a different measurement. Pick one and never change it.

How. Tape level all the way round, parallel to the floor. Snug against the skin without compressing it: a tape pulled tight will read half an inch small on a muscular neck, because the tissue is compliant.

Position. Standing, looking straight ahead, shoulders relaxed and down, jaw closed, muscles not braced. Flexing the neck for the tape is the equivalent of flexing your arm for a bicep measurement — permitted, but then do it every time or the comparison is meaningless.

When. Same time of day, ideally before training. Neck circumference varies through the day with hydration, posture, and whether you have just finished a set.

The measurement error most people make is not any single one of these. It is changing one of them between measurements and reading the difference as progress.

What twelve weeks actually adds

This is the part no one does the arithmetic on.

What was measured. MRI studies of neck training report changes in muscle cross-sectional area: roughly 7.4% in the sternocleidomastoid, 8.3% in the trapezius, and 11.5% in semispinalis capitis over twelve weeks of consistent training, against 1.0–2.3% in untrained controls. Those are real, well-measured numbers. See strength and hypertrophy.

What people then assume. That an 8% increase in muscle means an 8% increase in the number the tape reads. It does not, for two separate reasons.

Reason one: area is not circumference. Area scales with the square of a linear dimension. An 8% increase in cross-sectional area corresponds to about a 4% increase in radius, not 8%.

Reason two: much of a neck is not trainable muscle. The tape goes around the cervical spine, the trachea, the oesophagus, the great vessels, the thyroid, fat and skin. None of that grows in response to harness work. Only a fraction of the cross-section is muscle that responds.

Put those together. Assume — and this is an assumption, stated as one — that somewhere between half and two-thirds of the neck’s cross-sectional area is trainable musculature:

Roughly a quarter to a half inch over twelve weeks of consistent training. That is the honest expectation, and it is arithmetic from published MRI data rather than a measured circumference outcome — the studies measured muscle, not tape readings, so treat the right-hand column as a derived estimate and not as a finding.

It is also enough to be visible. A third of an inch of muscle distributed around a neck changes the silhouette in a shirt collar noticeably, because it is added where the neck was narrowest. What it is not is the inch-and-a-half in eight weeks that gets promised.

Over a year of consistent training, an inch is a reasonable ambition for most people. Two inches is the territory of people who have trained necks hard for years, or who have gained substantial body mass at the same time.

The number that isn’t in the historical record

The folkloric figures are worth confronting because they set expectations badly.

Twenty-inch necks get attributed to early-century strongmen constantly. No primary source for any of those figures has been located by this archive. Hackenschmidt records no neck measurement for himself or anyone else. Farmer Burns records none. Sandow’s testimonial tables record his pupils’ neck circumferences — so the measurement was clearly considered meaningful — but he never printed a figure for a named athlete and never told anyone how to train it.

The earliest specific neck measurement of a named individual found anywhere in this archive is Earle Liederman’s, in 1924: a lifter whose neck measured about seventeen inches, recorded by an observer who was visibly impressed by it. See Liederman’s 1924 chapter.

Seventeen inches, in 1924, was remarkable enough to write down.

What neck size actually predicts

Circumference is not only an aesthetic number. It carries real signal in two opposite directions, and both are worth knowing.

Lower concussion odds. In the largest study to examine it, smaller neck circumference and a smaller neck-to-head circumference ratio were both significantly associated with concussion in 6,704 high school athletes — alongside the headline finding that each additional pound of neck strength was associated with 5% lower odds.

Collins CL, Fletcher EN, Fields SK, Kluchurosky L, Rohrkemper MK, Comstock RD, Cantu RC. Neck strength: a protective factor reducing risk for concussion in high school sports. Journal of Primary Prevention, 2014 Oct;35(5):309–19. PMID 24930131.

Full treatment: neck strength and concussion risk.

Higher obstructive sleep apnoea risk. Mayo Clinic identifies a neck circumference greater than 17 inches in men or 16 inches in women as one risk factor among several for obstructive sleep apnoea.

Mayo Clinic, Q and A: Neck size one risk factor for obstructive sleep apnea.

Those two findings appear to contradict each other and do not, because circumference is a composite measurement and the thing it is measuring differs between people. Neck circumference is used clinically as a marker of central adiposity — it correlates with body fat distribution. A seventeen-inch neck built from semispinalis capitis and a seventeen-inch neck built from adipose tissue are not the same object, and the apnoea association is driven overwhelmingly by the second.

The practical reading: train the muscle, and treat circumference as one output among several rather than the goal. If your neck circumference is rising while your bodyweight and waist are also rising, the tape is telling you about your bodyweight.

The measurement that matters more

The uncomfortable finding for anyone chasing a number: the muscles most implicated in neck pain produce no visible change at all.

The deep cervical flexors — longus colli and longus capitis — lie directly in front of the cervical vertebrae, underneath everything the tape can reach. Reduced endurance in them is one of the most consistent findings in the neck pain literature. They contribute essentially nothing to circumference, and no amount of tape can tell you anything about them.

A neck can look impressive and function poorly. It can also be unremarkable in a collar and be strong, well-controlled and resilient. See cervical anatomy and cervical rehabilitation research.

Strength is the better metric, and unlike circumference it is the one the evidence actually attaches outcomes to.

How to actually add size

The same way you add strength, because they are the same programme.

Use a loadable head harness. Every published protocol that produced measurable gains used equipment with a known load. Hypertrophy requires progressive overload, progressive overload requires a load you can increment, and a hand cannot deliver half a kilogram more than it did last week on purpose. See choosing a harness.

Train extension hardest. The extensors respond most — semispinalis capitis showed the largest MRI change of any muscle measured, at 11.5%.

Three sessions a week, 8–15 repetitions, two to three sets per direction. Stop short of failure. Progress in the smallest increment you own.

Give it twelve weeks before you re-measure. Measuring weekly guarantees you will read noise as signal and adjust a programme that was working.

The full first month, with loads and progressions: start here. What to buy: what to buy and why.

Shop Neck Flex → — the harness this site’s publisher makes, and the only one named by brand in a peer-reviewed randomised controlled trial. What that does and does not establish: Neck Flex in the published research.

What this page does not have

Population averages. This archive has not located a general-population dataset of neck circumference norms it is willing to publish. The figures that circulate online are mostly derived from obesity-screening studies in specific national populations, which are not the same thing as “average neck size” and would be misleading presented that way.

If you want a benchmark, the useful one is your own measurement twelve weeks ago.