Height comparison: compare heights side by side
Compare two to four heights to scale and see the exact gap in centimetres and inches. Runs in your browser and sends nothing.
Reviewed by Dr. Aman Khanna, M.S. Orthopaedics, an orthopaedic surgeon. Limb lengthening is bone surgery, not physiotherapy.
Enter up to four people.
Name and sex are optional. Sex is only used for the country-average line.
For adults aged 18 and over whose growth plates have closed.
Enter at least one height to see the figures, and two to see the difference.
How to measure height correctly
Measure in the morning if you can. The discs between the vertebrae compress under load during the day, so the same person is a little shorter in the evening. In a small study of eight young adults the average difference across the day was 19.3 mm (1.1% of stature), and 54% of the daily loss happened in the first hour after getting up (PMID 4002039).
- Take off shoes, thick socks and any hair ornaments, and let the hair lie flat.
- Stand with heels, buttocks, shoulder blades and the back of the head against a flat wall, feet together.
- Look straight ahead so the line from the corner of the eye to the ear opening is level.
- Ask someone to lay a flat book or ruler on the crown, square to the wall, and mark the wall under it.
- Measure from the floor to the mark. Repeat once and use the average if the two readings differ.
Why a height difference feels bigger than it is
From crown to chin an adult head is roughly 22 to 23 cm. A 10 cm gap between two people is therefore close to half a head, and that is what the eye notices: the shorter person's crown sits near the taller person's eye line. As a share of height it is small, about 6% of a 170 cm person.
Distance changes the angle too. The angle you tilt your gaze is arctan(difference / distance). For a 10 cm difference that is about 5.7 degrees at 1 m and about 11.3 degrees at half a metre, so the same gap feels larger the closer people stand.
Shoes, hair, posture and camera position add to the impression, which is why the tool compares bare-foot heights measured the same way.
What limb lengthening can and cannot change
Limb lengthening is bone surgery, not stretching or physiotherapy. The bone is cut and then lengthened slowly over an intramedullary nail. Risks come first. A review of the published literature on limb lengthening in general reports a wide range of complication rates, up to 100% of treated cases in some series (PMID 32140790). A small cosmetic nail series of nine patients recorded insufficient bone regeneration, quadriceps contracture and a runaway locking screw (PMID 32055149). Other published risks include infection, nerve injury, joint stiffness and nonunion (PMID 32140790).
The gain is up to about 6 cm per segment (tibia or femur), decided from X-rays, and recovery takes 12 to 18 months for cosmetic cases. No surgeon can promise a specific number. Whether a person is a candidate is decided in a consultation, from imaging.
See our services and the height-after-LON calculator.
Average heights used
Mean height of 19-year-olds in 2019, by sex, from NCD Risk Factor Collaboration (NCD-RisC) estimates. Age 19 is close to final stature, but it describes a young cohort: older adults are often shorter, because average height has risen across generations in many countries (PMID 27458798). An average describes a population, not a norm for one person.
| Country | Men, age 19 (cm) | Women, age 19 (cm) |
|---|---|---|
| United Kingdom | 178.2 | 163.9 |
| United States | 176.9 | 163.3 |
| India | 166.5 | 155.2 |
| Pakistan | 167.3 | 154.8 |
| Saudi Arabia | 170.7 | 158.8 |
| United Arab Emirates | 174.1 | 160.5 |
| Iraq | 173.8 | 158.7 |
| Kuwait | 175.0 | 160.1 |
| Oman | 171.7 | 158.4 |
| Qatar | 173.3 | 160.7 |
| Egypt | 174.6 | 160.9 |
| Jordan | 174.8 | 159.5 |
| Turkey | 176.4 | 161.8 |
| Netherlands | 183.8 | 170.4 |
| Nigeria | 171.6 | 158.1 |
Frequently asked questions
How do I calculate the height difference between two people?
Subtract the shorter height from the taller one in the same unit. For 178 cm and 165 cm the difference is 13 cm, about 5.1 inches (1 inch is 2.54 cm). The tool does this for every pair among the people you enter and shows centimetres and inches together.
Where do the country averages come from?
They are NCD Risk Factor Collaboration estimates of mean height at age 19 in 2019 (Lancet 2020, PMID 33160572), downloaded from ncdrisc.org on 8 October 2026. The same group's earlier analysis of adult height trends was published in eLife in 2016 (PMID 27458798). Averages describe populations and say nothing about whether one person is tall or short.
Why does my height change between morning and evening?
The discs between the vertebrae lose some thickness under the load of standing and recover while lying down. In a small study of eight young adults the average daily change was 19.3 mm, or 1.1% of stature, and over half of it happened within an hour of getting up (PMID 4002039). Measure at the same time of day, shoes off, each time.
Can limb lengthening close a height difference between two people?
Only within limits and only after assessment. The gain is up to about 6 cm per segment, decided from X-rays, with 12 to 18 months of recovery for cosmetic cases, and the surgery carries risks that are published in the literature (PMID 32140790). Only imaging at consultation can decide that.
References
- NCD Risk Factor Collaboration. A century of trends in adult human height. eLife 2016. (PMID 27458798)
- NCD Risk Factor Collaboration. Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants. Lancet 2020. (PMID 33160572)
- Tyrrell AR, Reilly T, Troup JD. Circadian variation in stature and the effects of spinal loading. Spine 1985. (PMID 4002039)
- Hosny GA. Limb lengthening history, evolution, complications and current concepts. J Orthop Traumatol 2020. (PMID 32140790)
- Havitcioglu H, Gursan O, Isin Y. Cosmetic bilateral leg lengthening using intramedullary nail experience of 9 cases. J Orthop 2020. (PMID 32055149)
Country data: ncdrisc.org, Lancet 2020 height dataset, accessed 8 October 2026.
Contact
Candidacy for limb lengthening is decided at a consultation from X-rays. Send a message on WhatsApp or email and we reply within two business days.