Height comparison
See how a given height compares with others.
Tool · Height after LONالنسخة العربية
Limb lengthening height calculator
Estimate your height after lengthening over nail (LON), one segment at a time.
Reviewed by Dr. Aman Khanna, M.S. Orthopaedics, an orthopaedic surgeon. Limb lengthening is bone surgery, not physiotherapy.
Estimate your height after LON
For adults aged 18 and over whose growth plates have closed.
Educational estimate only. This tool is not a surgical plan and does not predict your result. Whether you are a candidate, and the actual target for each segment, are decided at consultation from standing long-leg X-rays and a psychological assessment. Risks come before benefit: ankle and joint stiffness or deformity, deformation of the new bone (PMID 32670567), hardware failure, malunion or nonunion, nerve entrapment and contractures (PMID 40051788) are all described in the published series, with figures below.
Your estimate
Estimate, not a prediction.
Enter your height to see the estimate.
Sitting-height note. The sitting-height ratio is sitting height divided by stature (PMID 20617018). Sitting height (trunk and head) does not change, so after the legs are lengthened this ratio falls.
How the estimate is made
Starting lengths. If you enter tibia and femur lengths we use them. If not, we estimate them from your height with ratios from 66,730 leg DXA scans in UK Biobank: the femur is about 0.252 of height in men and 0.251 in women, the tibia about 0.214 and 0.211 (PMID 42819027). The sample is British and about 90 percent white, and individual bones differ from the average by about 2 cm (one standard deviation is 21 to 22 mm in men), so this is an estimate. Your X-ray measurements will always be closer.
New height. Your height plus the gain you choose. This assumes the same gain on both legs and treats the full bone gain as standing height; a real result can differ.
Proportion check. The tibia : femur ratio is tibia length divided by femur length. The group means tabulated in PMID 42819027 (UK, Austrian, American and Japanese population samples) work out at about 0.80 to 0.85. This tool treats 0.78 to 0.88 as within range, 0.88 to 0.96 or 0.72 to 0.78 as a mild shift, and anything beyond as a marked shift. Those cut-offs are the tool's own guide band around the published means, not published thresholds. Measurement methods differ, people differ, and a ratio outside the band is not a diagnosis.
The cap. The sliders stop at 6 cm per segment. That is our planning rule, set for each person from X-rays, not a promise of 6 cm.
What limits the gain
Risks first. In the published cosmetic series the commonest problems are in the soft tissues around the bone, not the bone alone: ankle equinus was the commonest problem and obstacle, and deformation of the new bone and subtalar joint stiffness the commonest complications, in a systematic review of 795 patients (PMID 32670567), and a referral centre reported hardware failure in 23 percent and malunion or nonunion in 45 percent of 22 nail lengthenings done elsewhere (PMID 40051788). Those figures come from referred patients and are not a rate for all patients.
| Source | Patients | What it reports |
|---|---|---|
| Marwan 2020, systematic review (PMID 32670567) | 795, 11 studies | Mixed techniques (Ilizarov 34 percent, LON 32 percent, nail 8 percent). Mean gain 6.7 cm (range 1.5 to 13.0). Per patient: 0.78 problems, 0.94 obstacles, 0.15 complications. |
| Bulut 2025, meta-analysis (PMID 39801900) | 489, 7 studies | External fixator: problems 56 percent, obstacles 48 percent, complications 10 percent. Nail: problems 37 percent, obstacles 42 percent, no significant complications reported. |
| Novikov 2014, Ilizarov frame (PMID 25183215) | 131 | Mean gain 6.9 cm. 59 complications in 48 patients (37 percent of patients); 28 percent of patients had soft-tissue and 17 percent bone complications. |
| Kocaoglu 2017, lengthening over nail (PMID 30399986) | 32 | Psychiatric evaluation was part of selection. 34 complications reported. |
| Havitcioglu 2020, intramedullary nail (PMID 32055149) | 9 | Mean gain 8.7 cm, mostly femurs. Insufficient regenerate in 2, quadriceps contracture in 1, locking screw runaway in 1. |
| Al Ramlawi 2025, referral series (PMID 40051788) | 22 procedures | Hardware failure 23 percent, malunion or nonunion 45 percent. Patients were referred because of complications. |
Problems, obstacles and complications follow the Paley classification, in rising order of seriousness. Definitions and follow-up differ between studies, so the rows cannot be added together. All figures are from the literature, none is this clinic's own series.
Why about 6 cm per segment. It is our planning rule, set for each person from X-rays; it is not derived from a published limit. At typical lengths 6 cm is about 12 to 18 percent of a femur or tibia. Published mean cosmetic gains are 6.7 to 7.2 cm (PMID 32670567, PMID 27837313); those series come from other centres and are not our targets. The tibia and femur are separate segments, each lengthened in its own stage, so a plan for both is two operations with two recoveries, not one larger one.
Why 6 to 8 inches is outside our planning rule
Six to eight inches is 15 to 20 cm. The largest single gain in the systematic review above was 13.0 cm, about 5 inches, and the mean was 6.7 cm, about 2.6 inches (PMID 32670567). Gains approaching that size have been reported in achondroplasia, a different population in which several segments are lengthened over several stages (PMID 27512222). For a person of average proportions, 6 to 8 inches would need both segments and repeated stages, with higher risk, and would push the tibia : femur ratio well outside the guide band above. This calculator does not model it. Our planning rule is up to about 6 cm per segment.
What the 12 to 18 month recovery looks like in stages
Twelve to eighteen months from surgery to full activity is our planning figure for cosmetic cases; published treatment periods vary, from 7 to 18 months in one frame series (PMID 27837313). The bands below are indicative. Your own timeline is set from X-rays.
Month 0 to 1
Surgery and first weeks
Hospital stay and pain control; physiotherapy starts early.
Months 1 to 3
Lengthening phase
The bone is lengthened in small daily steps while X-rays track the new bone. The rate is set by the surgeon; in one series of 57 nail lengthenings a rate above 1.5 mm a day went with insufficient bone regenerate (PMID 20638660).
Months 3 to 9
Consolidation
The new bone hardens. Weight bearing increases in steps as X-rays allow. Joint movement and muscle strength are worked on every week.
Months 9 to 18
Return to full activity
Running, sport and strength usually return last, when X-rays allow; some people take longer. If both segments are planned, the second stage is scheduled after the first, so the total span is longer; the timeline is set at consultation.
References
- Alomar F, et al. Analysis of leg bone lengths from whole-body dual-energy X-ray absorptiometry in the UK Biobank. BJR Artif Intell. 2026;3(1):ubag014. PMID 42819027
- Marwan Y, et al. Cosmetic stature lengthening: systematic review of outcomes and complications. Bone Joint Res. 2020;9(7):341-350. PMID 32670567
- Bulut H, et al. Meta-analysis of complications and functional outcomes in cosmetic limb lengthening. J Orthop. 2025;65:41-45. PMID 39801900
- Al Ramlawi A, et al. Complications after cosmetic limb lengthening, a specialized center experience. J Orthop. 2025;61:7-11. PMID 40051788
- Novikov KI, et al. Cosmetic lower limb lengthening by Ilizarov apparatus: what are the risks? Clin Orthop Relat Res. 2014;472(11):3549-3556. PMID 25183215
- Kocaoglu M, et al. Results of cosmetic lower limb lengthening by the lengthening over nail technique. Acta Orthop Belg. 2017;83(2):231-244. PMID 30399986
- Havitcioglu H, et al. Cosmetic bilateral leg lengthening using intramedullary nail experience of 9 cases. J Orthop. 2020;20:232-235. PMID 32055149
- Guerreschi F, et al. Cosmetic lengthening: what are the limits? J Child Orthop. 2016;10(6):597-604. PMID 27837313
- Chilbule SK, et al. Limb lengthening in achondroplasia. Indian J Orthop. 2016;50(4):397-405. PMID 27512222
- Bogin B, Varela-Silva MI. Leg length, body proportion, and health: a review with a note on beauty. Int J Environ Res Public Health. 2010;7(3):1047-1075. PMID 20617018
- Kenawey M, et al. Leg lengthening using intramedullary skeletal kinetic distractor: results of 57 consecutive applications. Injury. 2011;42(2):150-155. PMID 20638660
Questions people ask
How much height can limb lengthening add?
In our planning, up to about 6 cm per segment, decided from X-rays. The tibia and femur are separate segments, so lengthening both in stages can add more in total; this calculator caps the total at 12 cm. Published cosmetic series report a mean gain of about 6.7 cm, with a range of 1.5 to 13.0 cm, across 795 patients (PMID 32670567). Each extra centimetre adds time and risk, and some people are not candidates.
Is leg lengthening surgery of 6 to 8 inches possible?
Not as a single plan for most people. Six to eight inches is 15 to 20 cm; the largest single gain in a systematic review of cosmetic lengthening was 13.0 cm (PMID 32670567). Gains approaching that size have been reported in achondroplasia, a different population in which several segments are lengthened over several stages (PMID 27512222). It would need both segments and repeated stages, with higher risk and unusual proportions.
How accurate is this height calculator?
It is an estimate. Without measured bone lengths it uses average femur and tibia proportions from UK Biobank DXA scans (PMID 42819027), and individual bones differ from those averages by about 2 cm. It also assumes equal gain on both legs. It cannot see your knee, ankle or soft tissue. Candidacy and the actual target are decided at consultation from standing long-leg X-rays.
Why does the tibia to femur ratio matter?
Lengthening one segment changes the shape of the leg as well as its length. The group means in PMID 42819027 sit at about 0.80 to 0.85; this tool treats 0.78 to 0.88 as within range, a guide band of its own and not a published threshold. Tibia-only lengthening is the commonest approach in published cosmetic series (124 of 131 patients in one, PMID 25183215), so an out-of-range ratio is expected; the question for the surgeon is whether the result is proportionate and functions well.
Who decides whether I am a candidate?
The surgeon, at consultation, after standing long-leg X-rays, an examination and a psychological assessment. Published centres include psychiatric evaluation in selection (PMID 30399986) and recommend psychosocial support alongside surgery (PMID 39801900). Recovery is 12 to 18 months for cosmetic cases. You can start by message on WhatsApp or email.
Related tools and next steps
Cost calculator
Work out the cost for the segments you are considering.
Services
What we operate on, and what we do not.
Contact the surgeon
Send your height, age and the X-rays you have. Candidacy and the target for each segment are decided at consultation, after a psychological assessment. This page is information, not a plan.