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This page describes products and general use; it is not medical advice.
What is a stadiometer?
A stadiometer is a device for measuring standing height (stature). The CDC describes it as a wall-mounted or portable unit designed solely to measure height, and calls it the preferred equipment for assessing height; the CDC school guidance gives measurement to the nearest one-eighth inch as the target resolution. Clinic staff, school and public-health screeners, and survey teams use it to measure height with a fixed vertical surface and a headpiece rather than a free-hand reading.
Who uses it: clinic and exam-room staff, school health programs and national health surveys. Buyers and students use this page to understand the parts, the types, and what correct measurement and upkeep involve.
How a stadiometer is built
The CDC’s school measurement guidance says a stadiometer can include a vertical board, a metric tape and a horizontal headpiece that slides down to measure height. The NHANES anthropometry manual describes the survey version as a fixed vertical backboard with an adjustable headpiece, where a digital measurement device is attached to an acrylic headpiece and the headpiece slides along an aluminum track on the measurement column.
- Backboard or column: the vertical surface the person stands against.
- Headpiece: the sliding horizontal piece that is lowered onto the top of the head.
- Scale or digital readout: a metric tape in the CDC school description; a digital measurement device in the NHANES version.
- Brake lever: in the NHANES setup the headpiece is slid to the top of the column and locked with a brake lever between people.
Types and variants
| Type | Typical use | Key difference | Source |
|---|---|---|---|
| Wall-mounted | Height measurement at a fixed location | Mounted to a wall | CDC Healthy Schools, BMI Measurement in Schools |
| Portable | Height measurement where a wall mount is not used | Portable unit rather than a wall-mounted one | CDC Healthy Schools, BMI Measurement in Schools |
| Digital readout | National survey measurement | A digital measurement device attached to the headpiece, linked electronically to the survey system | CDC/NCHS NHANES Anthropometry Procedures Manual (2021) |
A stadiometer measures standing height. In the NHANES manual it is used for people aged 2 years and older, while a separate device, the infantometer, measures recumbent (lying) length from birth through 47 months.
Specifications that matter
The one specification the CDC school guidance names is resolution: measurement to the nearest one-eighth inch. Other dimensions such as column height or capacity vary by product and are given in the manufacturer’s specification sheet.
How to choose
Two criteria come from the CDC sources. First, the CDC school guidance calls for a unit designed solely to measure height, either wall-mounted or portable, with one-eighth inch resolution. Second, the survey protocol relies on a rigid backboard and a headpiece that slides smoothly and locks, so confirm the headpiece moves freely and stays in place. Everything else, including range and accessories, is set by the manufacturer’s specifications and your own use.
Safe use and handling basics
The NHANES protocol, a research survey procedure that clinics often adapt, positions the person as follows:
- Hair ornaments, jewelry, buns and braids that interfere are removed.
- The person stands straight against the backboard with weight even, both feet flat, heels together and toes apart at roughly a 60 degree angle.
- The back of the head, shoulder blades, buttocks and heels touch the backboard, although this is not always possible, for example with kyphosis.
- The head is in the Frankfort horizontal plane: an imaginary line from the ear canal to the lower border of the eye socket, parallel to the floor and perpendicular to the backboard, looking straight ahead.
- The headpiece is lowered to rest firmly on the head with enough pressure to compress the hair. The person stands as tall as possible and takes a deep breath, which straightens the spine for a reproducible reading; the value is then recorded.
If hair style or shoes interfere, the NHANES team measures the hair piece or heel with a 15 cm plastic ruler and applies a correction. If the digital device fails, a tape measure mounted on the side of the column is the backup.
Calibration and upkeep
NHANES calibrates its stadiometer with a 100 cm metal rod at the start of each stand, daily, and at the end of the stand. The rod stands on the base perpendicular to it with the headpiece resting on top, and the reading should be 100.0 cm; if not, the device is recalibrated to 100.0 cm. For cleaning, the acrylic headpiece is wiped with alcohol wipes and the digital device with a dry cloth, with no fluid into the housing. The aluminum track is wiped with a damp cloth and lubricated with sewing machine oil as needed. For background on calibration in general, see what calibration is.
Common mistakes
- Leaving hair ornaments, braids or buns in place, which stop the headpiece resting on the head.
- Head not level: the Frankfort plane is the reference, not a comfortable pose.
- Skipping the deep breath and stand-tall instruction, which the protocol uses to get a reproducible stature.
- Not checking against a reference length. The NHANES team checks the device against a 100 cm rod on a schedule rather than assuming it stays accurate.
- Using a standing stadiometer for infants. The survey uses a separate infantometer for length from birth through 47 months.
Frequently asked questions
What is a stadiometer used for?
Measuring standing height. The CDC lists it as the preferred equipment for assessing height, including in school programs and national surveys.
What are the main parts of a stadiometer?
A vertical board or backboard, a sliding horizontal headpiece, and a tape or digital readout, per the CDC school guidance and the NHANES manual.
How is a stadiometer different from a measuring tape?
It holds the person against a fixed vertical surface and uses a headpiece perpendicular to it. The NHANES team keeps a tape measure on the column only as a backup if the device fails.
Related pages and equipment
Related reading on CASRAI: what a medical thermometer is, what a blood pressure cuff is, and the pediatric clinic supply checklist. Equipment of this kind is listed under diagnostic, monitoring and imaging products.
Sources
- CDC/NCHS, National Health and Nutrition Examination Survey Anthropometry Procedures Manual, May 2021, https://wwwn.cdc.gov/nchs/data/nhanes/public/2021/manuals/2021-Anthropometry-Procedures-Manual-508.pdf (checked 2026-10-30).
- CDC Healthy Schools, BMI Measurement in Schools, Safeguard 4 (archived), https://archive.cdc.gov/www_cdc_gov/healthyschools/obesity/bmi/bmi_measurement_schools_safeguard4.htm (checked 2026-10-30).
