FitCalcs

BMI for 5'6" & 100 lbs

Result: 16.1 ยท Moderate Thinness

Body Mass Index

16.1

Moderate Thinness

WHO BMI range for this category: 16 โ€“ 16.9

What a BMI of 16.1 at 5'6" and 100 lbs means

A body mass index of 16.1 (5'6", 100 lbs) falls between severe and mild thinness. Without a deliberate sport-related reason, this band warrants a closer look at protein intake, total calories, and possible undiagnosed gastrointestinal conditions.

For someone 5'6" tall, the WHO healthy BMI range (18.5 โ€“ 24.9) corresponds to a body weight between roughly 52.2 โ€“ 70.3 kg (115.1 โ€“ 154.9 lbs). BMI is a screening tool, not a body composition measurement, so it does not distinguish muscle from fat. Pair it with waist circumference and body fat percentage for a complete picture.

What you would need to weigh at 5'6" to reach each BMI threshold

Target BMIBody weightDifference vs current
BMI 18.5 (underweight cutoff)52.2 kg (115.1 lbs)+6.9 kg
BMI 22 (middle of healthy range)62.1 kg (136.9 lbs)+16.7 kg
BMI 25 (overweight cutoff)70.6 kg (155.6 lbs)+25.2 kg
BMI 30 (obesity cutoff)84.7 kg (186.7 lbs)+39.3 kg

BMI for nearby heights and weights

Reference values at similar measurements. Each link is a pre-calculated page.

HeightWeightBMICategory
5'6"90 lbs14.5Severely Underweight
5'6"110 lbs17.7Mildly Underweight
5'6"120 lbs19.3Normal weight
5'4"100 lbs17.1Mildly Underweight
5'8"100 lbs15.2Severely Underweight
5'6"130 lbs20.9Normal weight
5'4"90 lbs15.4Severely Underweight
5'4"110 lbs18.8Normal weight

Looking for the metric equivalent? See BMI for 170 cm & 45 kg โ†’

Frequently asked questions

Is a BMI of 16.1 healthy for 5'6"?
A BMI of 16.1 at 5'6" is classified as Moderately Underweight. The WHO healthy BMI range is 18.5 โ€“ 24.9, which for your height translates to roughly 52.2 โ€“ 70.3 kg (115.1 โ€“ 154.9 lbs).
What is the ideal weight for someone 5'6" tall?
The mid-point of the healthy BMI range (BMI 22) for 5'6" is approximately 62.1 kg (136.9 lbs). The full healthy range spans roughly 52.2 โ€“ 70.3 kg. Body composition matters more than the exact number โ€” a muscular person can sit at the top of the range and be perfectly healthy.
How does BMI relate to body fat percentage at 100 lbs?
BMI does not measure body fat directly. Two people at 5'6" and 100 lbs can have very different body compositions. A trained athlete at this weight may have 12 โ€“ 15% body fat, while a sedentary adult may have 25 โ€“ 30%. Use the Body Fat Calculator for a more precise estimate.
Is BMI accurate for everyone at 5'6" tall?
BMI is a population-level screening tool. It systematically over-classifies muscular athletes as overweight and under-classifies older adults with sarcopenic obesity. For an individual assessment at 5'6", combine BMI with waist circumference (men < 94 cm, women < 80 cm at low risk) and body fat percentage.
How much weight would I need to lose or gain to reach a healthy BMI at 5'6"?
If your BMI is below 18.5, gaining weight up to the 52.2 kg (115.1 lbs) threshold puts you in the healthy band. If above 25, losing weight toward 70.3 kg (154.9 lbs) does the same. Aim for 0.25 โ€“ 0.5 kg per week for sustainable change.

Calculate with your own values

This page shows pre-calculated results for 5'6" and 100 lbs. For any other combination, use the full calculators below.

Disclaimer: BMI is a population-level screening tool, not a diagnostic measure. This page is for informational purposes only and is not medical advice. Consult a qualified healthcare professional before making weight or health decisions.