What BMI is ideal for climbing?

There is no evidenced value for that. What does exist are measurements: in a survey of 498 sport climbers from 33 countries the average BMI was 22.7, 22.9 among the men and 21.9 among the women — each with a spread of around 2.5 points. That is the average of a group and not a target for an individual. Turning an average into a goal is a fallacy: half of all the climbers measured were below it, the other half above, and both climb.

Will I get better if I lose weight?

What counts for performance is strength relative to bodyweight — and that can be changed from either side of the fraction. But the route via eating less has a catch: if less energy is available over a long period than training and basal metabolism consume, the very things climbing depends on suffer. The International Olympic Committee groups this under the term REDs, a syndrome of health and performance consequences of too low an energy intake. Documented effects include falling bone density, changes in hormone balance and a weakened immune system. Building strength and technique improve the same ratio without that price.

Do different thresholds apply to women?

Not in the WHO classification for adults: the same thresholds apply regardless of sex. The climbing world federation IFSC used different trigger values in its earlier procedure — 18.5 for men and 17.5 for women. Those were not targets but thresholds at which the athlete and the national federation were informed. Since February 2024 the federation no longer relies on a single BMI value.

I have a lot of muscle — is my value still valid?

BMI does not distinguish between muscle, fat and bone; it knows only weight and height. The Austrian health portal points out explicitly that people with a high proportion of muscle can have a high BMI without being overweight. The reverse holds too: a value in the normal range does not prove that energy intake is adequate. As a measure on its own, BMI says little — that is not outside criticism, it is what the official classification itself states.

When should I talk to someone about this?

A value below 18.5 is reason for a medical assessment, especially with unintended weight loss — which is often a sign of illness. The same applies to missed periods, frequent infections, poor recovery, recurring injuries or persistent tiredness. And regardless of any number: if thoughts about food, weight or body shape take up a lot of space, that is reason enough in itself. The eating disorder hotline run by Wiener Gesundheitsförderung offers free, anonymous advice on +43 800 20 11 20, Monday to Thursday from 12 to 5 p.m. It is an Austrian service and advice is given in German.

BMI calculator for climbers: what the number says

Work out your BMI and put it in context — with the limits of the measure, the values recorded from 498 climbers and what the world federation IFSC learned from them.

Last updated: 27 July 2026

Units

Height

Measured without shoes.

Bodyweight

Varies noticeably over the day — your morning value is the most useful one.

Your result

Enter both values — the result appears straight away.

The classification at a glance

The same thresholds apply to women and men. They come from statistics on large populations, not from studies of athletes.

Category	BMI
Underweight	under 18.5
Normal weight	18.5 to under 25
Overweight	25 to under 30
Obesity class I	30 to under 35
Obesity class II	35 to under 40
Obesity class III	40 and above

The classification applies to adults. For children and adolescents, weight is assessed using percentile curves that take age and sex into account — this calculator is not built for that.

Why there is no target weight here

The most searched question around BMI and climbing is how light you should be. This page does not answer it, and that is not evasion. There is simply no study from which a target weight for an individual could be derived — but there are studies of what happens when climbers take that question seriously and act on it.

The largest survey on the subject to date questioned 498 sport climbers from 33 countries. One finding: those who climb better had a lower BMI on average. The second finding appears in the same publication — among the women in the two highest ability groups, 42.9 per cent showed signs of disordered eating, nine out of twenty-one. Both findings belong together. Passing on only the first tells the story the wrong way round.

What BMI measures — and what it does not

The calculation could hardly be simpler: bodyweight in kilograms divided by height in metres squared. But that is exactly where the limits come from. Two numbers go into the formula, and neither says anything about what that weight is made of.

The Austrian health portal puts it plainly: as a measure on its own, the body mass index says little. It ignores fat distribution, body composition and the ratio of muscle to fat mass; age and sex do not appear at all. People with a high proportion of muscle can have a high value without being overweight. The World Health Organization describes BMI as a proxy for body fat and points out that further measurements are needed for a diagnosis.

Just how crude the measure is, the calculator above shows in passing: at a height of 175 centimetres, every weight between roughly 57 and 76 kilograms falls into the same band. Twenty kilograms of difference, one category. For statistics on millions of people that resolution is enough. For the question of whether your training currently suits you, it is not.

And one more limitation that often gets lost: the classification applies to adults. For children and adolescents, weight is assessed using percentile curves that take age and sex into account. The calculator on this page is not built for that.

What the world federation learned from it

The climbing world federation IFSC had every reason to want a simple number: a threshold is quick to check and easy to enforce. Its earlier procedure had one — 18.5 for men, 17.5 for women. If it was undercut, the athlete and the national federation were informed.

In February 2024 the federation replaced that procedure, becoming the first international governing body with a comprehensive framework against REDs. Instead of a single value there is now a multi-step process: questionnaires on energy availability and eating behaviour, baseline values such as height, weight, pulse and blood pressure, a health certificate from the national federation, further assessment with bone density measurement and blood values where anything stands out, and spot checks at competitions. Suspected cases go to an independent commission.

The federation’s reasoning is the same for everyone on the rock: a simple BMI value does not give an accurate picture of a person’s health, and excluding someone on that basis alone would be a serious infringement of their rights. If the number is not even enough to decide about a competition start, it is certainly not enough to decide about your training.

When too little energy arrives, day after day

Behind the abbreviation REDs stands a term from the International Olympic Committee: relative energy deficiency in sport. What is meant is not a dieting mistake but a state — over a longer period, less energy is available than training and basal metabolism consume. The committee describes the health and performance consequences that follow, expressly in women and in men.

What is at stake is listed by the Austrian health portal for pronounced underweight: reduced bone density up to osteoporosis, changes in hormone balance and menstruation, a weakened immune system, anaemia, a slowed heart rate. For a sport in which falls are part of everyday life and tendons and pulleys already work at the limit, the first point is the most uncomfortable.

This page is no substitute for medical advice, and a calculator makes no diagnosis. If your value is low, if you have lost weight unintentionally, if your periods have stopped, if you recover badly or if thoughts about food and weight take up a lot of space: talk to a doctor. In Austria the eating disorder hotline run by Wiener Gesundheitsförderung offers free, anonymous advice on +43 800 20 11 20, Monday to Thursday from 12 to 5 p.m., or by email to hilfe@essstoerungshotline.at.

Frequently asked questions

What BMI is ideal for climbing?: There is no evidenced value for that. What does exist are measurements: in a survey of 498 sport climbers from 33 countries the average BMI was 22.7, 22.9 among the men and 21.9 among the women — each with a spread of around 2.5 points. That is the average of a group and not a target for an individual. Turning an average into a goal is a fallacy: half of all the climbers measured were below it, the other half above, and both climb.
Will I get better if I lose weight?: What counts for performance is strength relative to bodyweight — and that can be changed from either side of the fraction. But the route via eating less has a catch: if less energy is available over a long period than training and basal metabolism consume, the very things climbing depends on suffer. The International Olympic Committee groups this under the term REDs, a syndrome of health and performance consequences of too low an energy intake. Documented effects include falling bone density, changes in hormone balance and a weakened immune system. Building strength and technique improve the same ratio without that price.
Do different thresholds apply to women?: Not in the WHO classification for adults: the same thresholds apply regardless of sex. The climbing world federation IFSC used different trigger values in its earlier procedure — 18.5 for men and 17.5 for women. Those were not targets but thresholds at which the athlete and the national federation were informed. Since February 2024 the federation no longer relies on a single BMI value.
I have a lot of muscle — is my value still valid?: BMI does not distinguish between muscle, fat and bone; it knows only weight and height. The Austrian health portal points out explicitly that people with a high proportion of muscle can have a high BMI without being overweight. The reverse holds too: a value in the normal range does not prove that energy intake is adequate. As a measure on its own, BMI says little — that is not outside criticism, it is what the official classification itself states.
When should I talk to someone about this?: A value below 18.5 is reason for a medical assessment, especially with unintended weight loss — which is often a sign of illness. The same applies to missed periods, frequent infections, poor recovery, recurring injuries or persistent tiredness. And regardless of any number: if thoughts about food, weight or body shape take up a lot of space, that is reason enough in itself. The eating disorder hotline run by Wiener Gesundheitsförderung offers free, anonymous advice on +43 800 20 11 20, Monday to Thursday from 12 to 5 p.m. It is an Austrian service and advice is given in German.

Measure what you can actually work on

Your weight says little about how you climb. Your ascents say a lot. In Chalkaholics you log them and see over the months where you are getting stronger — grades, volume, consistency. Those are numbers training can move.

Sources

Every number on this page comes from the publications below. None of it is estimated.

World Health Organization: Obesity and overweight. Fact sheet.The body mass index formula, the thresholds of 25 for overweight and 30 for obesity, and the classification of BMI as a proxy for body fat that does not replace further measurement.
Gesundheitsportal Österreich (Austrian Federal Ministry of Social Affairs, Health, Care and Consumer Protection): Body Mass Index (BMI).The complete classification table for adults from underweight to obesity class III, the note that BMI on its own says little and ignores body composition, fat distribution, age and sex, and the percentile curves for children and adolescents.
Gesundheitsportal Österreich: Untergewicht – Mangelernährung.The gradations of underweight below 18.5 and the documented consequences: reduced bone density up to osteoporosis, changes in hormone balance and menstruation, a weakened immune system, anaemia, a slowed heart rate. Plus the note that unintended weight loss often points to an illness.
Joubert LM, Blunt Gonzalez G, Larson AJ (2020): Prevalence of Disordered Eating Among International Sport Lead Rock Climbers. Frontiers in Sports and Active Living 2:86.498 sport climbers from 33 countries, average age 32; mean BMI 22.7 overall, 22.9 among men and 21.9 among women. Share showing signs of disordered eating (EAT-26 at 20 points or above): 8.6 per cent overall, 6.3 per cent among men, 16.5 per cent among women and 42.9 per cent among the women in the two highest ability groups.
Mountjoy M et al. (2023): 2023 International Olympic Committee’s (IOC) consensus statement on Relative Energy Deficiency in Sport (REDs). British Journal of Sports Medicine 57(17):1073–1097.Definition of REDs as a syndrome of health and performance consequences in women and men, triggered by too low an energy availability relative to what training consumes.
International Federation of Sport Climbing (2024): New competition policy places IFSC at forefront of fight against REDs.The structure of the procedure — questionnaires, a health certificate from the national federation, spot checks at competitions and an independent commission — and the IFSC’s statement that a simple BMI value does not give a reliable picture of health and that excluding someone on that basis alone would infringe athletes’ rights.
Inside Climbing (2024): Learn How the IFSC is tackling RED-S in World Cup Climbing.The former BMI trigger values of 18.5 for men and 17.5 for women and what followed if they were undercut, plus the components of the new procedure including bone density measurement and blood values.
Wiener Gesundheitsförderung: Hotline für Essstörungen.Anonymous and free advice for those affected and their families on +43 800 20 11 20, Monday to Thursday from 12 to 5 p.m., and by email to hilfe@essstoerungshotline.at.