Body Mass Index (BMI) Regex for Python

What this pattern does

This page provides a well-structured, multi-part regular expression for matching body mass index (bmi), ported and verified for Python. Identity and credential patterns need both correctness and safety, since they're frequent targets for adversarial input. The snippet below is ready to drop into your Python project — whether you're validating in a Django view, a FastAPI endpoint, or a standalone data processing script.

Python Implementation

# Body Mass Index (BMI)
# ReDoS-safe | RegexVault — Identity & PII > Biometric & Physical

import re

body_mass_index_bmi_pattern = re.compile(r'^(?:(?:[1-6][0-9](?:\.[0-9]{1,2})?)|(?:70(?:\.0{1,2})?))$')

def validate_body_mass_index_bmi(value: str) -> bool:
    return bool(body_mass_index_bmi_pattern.fullmatch(value))

# Example
print(validate_body_mass_index_bmi("22.5"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Identity & PII > Biometric & Physical category and carries a ReDoS-safe certification. That matters for Python developers because particularly important in Python web servers where CPU-bound regex operations can stall concurrent request handling. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Normal BMI range is 18.5-24.9. BMI is a derived health metric — stored in medical records, used in insurance underwriting. As a health data attribute, it falls under GDPR Article 9 sensitive data category when processed for medical purposes.