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# BMI calculator

How does the World Health Organisation (WHO) classify your weight? Enter your weight and height. The calculator will show your Body Mass Index (BMI), its category and the weight considered normal for your height. It is intended for adults aged 18 and over.

The calculator classifies your BMI and does not make a diagnosis. Whether treatment is appropriate cannot be determined from the BMI alone. This is clarified by a medical examination.

## How the calculator works

- ### Weight divided by height squared  
BMI is body weight in kilograms divided by the square of height in metres. 72 kg at 1.75 m gives 72 ÷ (1.75 × 1.75), rounded to 23.5.
- ### Rounded like the classification  
The calculator rounds the BMI to one decimal place, as the class limits are written, and classifies the rounded value: 24.9 still counts as normal weight, 25.0 no longer does.
- ### Normal weight in kilograms  
A BMI of 18.5 to 24.9 is considered a normal weight. The calculator shows which whole kilograms fall within this range for your height.

## BMI categories for adults

The classification comes from the World Health Organization (WHO). The German S3 guideline on the prevention and treatment of obesity uses it too.

| Category                 | BMI in kg/m² |
| ------------------------ | ------------ |
| Underweight              | < 18.5       |
| Normal weight            | 18.5–24.9    |
| Overweight (pre-obesity) | 25.0–29.9    |
| Obesity class I          | 30.0–34.9    |
| Obesity class II         | 35.0–39.9    |
| Obesity class III        | ≥ 40.0       |

## What the BMI does not show

- ### What body weight consists of  
The BMI does not distinguish between fat, muscle and bone. Very muscular people may have a high BMI simply because of their muscle mass.
- ### Where the fat is stored  
The BMI does not show how body fat is distributed. Other measurements, such as waist circumference, help to assess this.
- ### Age and gender  
For the same BMI, older adults have more body fat than younger people, and women have, on average, more than men. For older people, BMI is also a less reliable indicator of health risks.
- ### Children and adolescents  
For children and adolescents, classification depends on age and gender and is determined using comparative values for peers of the same age. The calculator is not intended for this purpose.

## Frequently Asked Questions

What is a normal BMI?

For adults, a BMI of 18.5 to 24.9 is considered a normal weight. A BMI of 25 or above is classified as being overweight, and 30 or above as obesity. The calculator shows how much this is in kilograms for your height.

At what BMI is excess weight treated?

The German guideline states that treatment is indicated for a BMI of 30 or above, or a BMI of 25 to just under 30 if one of the following additional conditions is present: weight-related health problems such as high blood pressure or type 2 diabetes, a waist circumference of 102 cm or more in men or 88 cm or more in women, conditions that are exacerbated by excess weight, or high psychosocial distress. Whether treatment is advisable depends on the overall picture and is determined during a medical examination.

Does health insurance cover weight-loss medication?

Statutory health insurance funds do not cover them: the law excludes medicines that are primarily intended for weight loss, appetite suppression or weight regulation from their benefits (§ 34(1) SGB V). If a doctor prescribes such a medicine, those with statutory health insurance must pay for it themselves. With private health insurance, it depends on your policy.

What is the DMP for obesity?

A structured treatment programme run by statutory health insurers for adults with obesity: comprising information, training and jointly agreed goals. Since 1 July 2024, health insurers have been able to conclude regional contracts for this purpose. Adults with a BMI between 30 and 35 and at least one comorbidity, such as high blood pressure or type 2 diabetes, as well as adults with a BMI of 35 or above, are eligible to take part. If your health insurance provider has such a contract, you can enrol at your GP’s practice. Medicines that suppress appetite are not included in this scheme.

Will my entries be saved?

No. The calculator performs its calculations within your browser; your input does not leave your device. Only if it cannot run there – for example, because JavaScript is disabled – will your browser send the input to our server for calculation. It is not stored there either.

## More on lokalmed

- [Pharmacological weight loss · Find doctors](https://lokalmed.de/en/treatments/weight-management)
- [Practices · Find practices](https://lokalmed.de/en/search/practices?treatment=weight%5Fmanagement)

## From the guide

- ### [How much does medication-based obesity treatment cost, and does health insurance cover it?](https://lokalmed.de/en/articles/obesity-treatment-costs-and-health-insurance-cmz6t7azyj)  
Medicines for weight loss are excluded from prescription coverage under statutory health insurance. Why the active ingredient, indicated use and reimbursement status differ; what costs are incurred when paying out of pocket; and what applies to private health insurance and government-subsidised health insurance.  
Redaktion·21 August 2026·6 min read
- ### [Weight-loss injections: effects, eligibility criteria, side effects and limitations](https://lokalmed.de/en/articles/weight-loss-injections-effects-requirements-and-side-effects-wpkeud0tz9)  
Prescription medicines for the treatment of obesity: how the active ingredients affect appetite and satiety, who they are authorised for, what side effects and warnings apply, and why the treatment must be considered as a long-term approach.  
Redaktion·21 August 2026·8 min read
- ### [Stopping weight-loss injections: What happens to your weight and appetite?](https://lokalmed.de/en/articles/stopping-weight-loss-injections-weight-and-appetite-lly8hsmoss)  
In studies, weight increased significantly on average after the end of treatment. What STEP-1 and SURMOUNT-4 actually investigated, why a returning appetite is not a matter of self-discipline, and what should be included in a prepared maintenance plan.  
Redaktion·21 August 2026·7 min read

## Sources

- [World Health Organization. Obesity and overweight. Fact sheet, 08.12.2025](https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight)
- [Deutsche Adipositas-Gesellschaft et al. Interdisziplinäre S3-Leitlinie Prävention und Therapie der Adipositas, Version 5.0, Oktober 2024\. AWMF-Register 050-001](https://register.awmf.org/assets/guidelines/050-001l%5FS3%5FPraevention-Therapie-Adipositas%5F2024-10.pdf)
- [§ 34 Sozialgesetzbuch V (SGB V)](https://www.gesetze-im-internet.de/sgb%5F5/%5F%5F34.html)
- [Gemeinsamer Bundesausschuss. Regionale Verträge für ein DMP Adipositas ab sofort möglich. Meldung, 01.07.2024](https://www.g-ba.de/presse/pressemitteilungen-meldungen/1196/)

The lokalmed editorial team last checked the calculation methods, texts and sources on 27 September 2026\. [How lokalmed works](https://lokalmed.de/en/about)