A Body Shape Index (ABSI) Calculator
ABSI (A Body Shape Index) combines waist circumference with BMI and height to measure abdominal fat distribution — a risk factor that BMI alone misses. Enter height, weight and waist measurement to compute your ABSI and see where it falls relative to the broad population.
Units
cm
kg
cm
Moderate relative risk
- 1
BMI
70 ÷ 1.7² = 24.22 kg/m² - 2
BMI^(2/3)
24.22^(2/3) = 8.371439 - 3
Height^(1/2)
√1.7 = 1.30384 - 4
ABSI denominator
8.371439 × 1.30384 = 10.915021 - 5
ABSI
0.8 ÷ 10.915021 = 0.0733Waist circumference (m) divided by (BMI^(2/3) × height^(1/2)).
How does this calculator work?
ABSI = WC(m) ÷ (BMI^(2/3) × height_m^0.5), where BMI = weight(kg)/height(m)². Values below ~0.073 suggest low relative central-obesity risk; above ~0.083 suggests higher risk, based on population data from Krakauer & Krakauer (2012). Results are informational, not clinical diagnoses — individual risk varies by age, sex and ethnicity.
Formula
How this is calculated
BMI correlates with total body fat but is blind to how that fat is distributed: a lean person with a large waist and a muscular person with the same weight and height get the same BMI. ABSI corrects for this by incorporating waist circumference (WC) directly. The formula — proposed by Krakauer & Krakauer in their 2012 PLOS ONE paper — divides WC by a body-mass-and-height scaling factor (BMI^(2/3) × height^(1/2)), producing an index where higher values indicate more abdominal ("central") fat relative to what you would expect for your size.
Central obesity, particularly visceral fat around the abdominal organs, is more metabolically active and carries greater health risks than subcutaneous fat on the hips and thighs. Studies have found ABSI to be an independent predictor of all-cause mortality even after adjusting for BMI. Measure waist circumference at the level of the navel (belly button) while relaxed and not holding your breath, as described in the original methodology.
The risk bands shown (< 0.073 low, 0.073–0.083 moderate, > 0.083 higher) are broad population averages derived from the Krakauer 2012 cohort and are not officially validated clinical cut-offs. ABSI also varies meaningfully by age and sex: values tend to be slightly higher in women and increase with age. These categories are indicative only — use the result as a conversation prompt with a healthcare professional, not as a diagnosis.
Frequently asked questions
BMI uses only weight and height with no waist measurement; it misses fat distribution. Waist-to-height ratio (WHtR) captures central fat but does not adjust for body mass. ABSI incorporates all three — waist, weight and height — and is mathematically constructed to be relatively independent of BMI, so it adds information that BMI does not provide. Research suggests ABSI predicts mortality risk independently of both BMI and WHtR.
Measure at the level of the navel (belly button) while standing and breathing normally. This differs from the WHO waist protocol (midway between the lowest rib and the iliac crest), so results may differ slightly if you use a tape measure placed higher. The Krakauer paper used the navel-level measurement, which is what this calculator assumes.
No. ABSI is a population-level statistical predictor, not a diagnostic tool. It does not account for muscle mass, ethnicity-specific risk thresholds, family history or clinical measurements. Use it as one data point among many, and discuss any health concerns with a qualified healthcare provider.
TG we-Calculate Editorial Team. (2026). A Body Shape Index (ABSI) Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/a-body-shape-index-calculator
TG we-Calculate Editorial Team. "A Body Shape Index (ABSI) Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/a-body-shape-index-calculator.
TG we-Calculate Editorial Team, "A Body Shape Index (ABSI) Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/a-body-shape-index-calculator
@misc{wecalculate_a_body_shape_index_calculator, title = {A Body Shape Index (ABSI) Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/a-body-shape-index-calculator}}, year = {2026}, note = {TG we-Calculate} }
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