ABSI Calculator
ABSI (A Body Shape Index) measures abdominal risk using waist, height and weight. Use our absi calculator to get an absi score instantly; the number helps estimate whether your body shape puts you at higher cardiometabolic risk than BMI alone.
What is ABSI?
ABSI, or A Body Shape Index, is a health metric that includes your waist circumference in addition to your weight and height. This allows ABSI to account for where fat is located on your body. Its main advantage is its ability to highlight the risks associated with belly fat (central adiposity), which has a stronger link to cardiovascular health issues than overall weight alone.
Two people can have the same BMI, but if one has more fat around their midsection, their ABSI will be higher—often signaling a greater health risk. This is why ABSI complements BMI, offering a more complete picture.
The ABSI Formula : A Step-by-Step Outline
Step 01
Calculate Your BMI
First, calculate your Body Mass Index using the standard formula: weight (kg) / height (m)².
Step 02
Process BMI and Height
Take your BMI to the power of 2/3 and your height to the power of 1/2 (the square root).
Step 03
Incorporate Your Waist
Divide your waist circumference (in meters) by the product of the two values from the previous step.
Step 04
Get Your ABSI Score
The resulting number is your raw ABSI score, a powerful indicator of your body shape.
Common Mistakes & Tips
- Always convert waist and height to **meters (m)**.
- To convert pounds to kg, divide by 2.20462.
- Using cm for waist and m for height will give a result ~100x too large.
1. BMI: 70 / 1.65² = 25.71
2. BMI²ᐟ³: 25.71^(2/3) ≈ 8.76
3. Height¹ᐟ²: √1.65 ≈ 1.28
4. ABSI: 0.90 / (8.76 × 1.28) ≈ 0.08043
- Stand and Relax: Stand upright but relaxed, and breathe out normally. Don't suck in your stomach.
- Find the Location: Measure just above your belly button, at the narrowest part of your torso.
- Use the Tape: Wrap a flexible measuring tape around your waist, ensuring it's level with the floor.
- Check the Fit: The tape should be snug against the skin but not tight enough to compress it.
- Record the Value: Note the measurement to the nearest 0.1 cm. Remember to convert it to meters for the formula!
Learning Your ABSI Score
A raw ABSI value is useful, but it becomes powerful when converted to an "ABSI Z-Score". This score compares your result to an age and gender-matched population, telling you how your body shape risk compares to the average. If you’d like to estimate your actual body fat percentage using a simpler method, try our RFM Calculator.
Keep up your healthy habits.
Focus on general prevention with diet and exercise.
Raise physical activity and consult a doctor.
ABSI Versus Other Body Indices
ABSI is one of several tools used to assess body composition. Here's how it compares to other common indices.
| Index | What It Measures | Strengths | Weaknesses |
|---|---|---|---|
| ABSI | Body shape and central fat relative to size. | Strongly tied to mortality risk; isolates belly fat. | Requires population data (z-scores) for context. |
| BMI | Overall body mass relative to height. | Simple, universal screening tool. | Doesn't distinguish fat from muscle; ignores fat location. |
| WHtR | Waist size relative to height. | Very simple; good predictor of cardiometabolic risk. | Doesn't account for overall body mass (weight). |
Fig 1: Same BMI, Different Risk. Higher ABSI indicates greater health risk.
Fig 2: ABSI helps estimate the risk from harmful visceral fat.
Real-Life Case Study: "Riya"
Meet Riya, a 28-year-old woman
Riya wanted to understand her health beyond the number on the scale. Her BMI was in the 'normal' range, but she was concerned about her body shape.
Weight: 60 kg
Height: 1.70 m
Waist: 72 cm (0.72 m)
Her Results & Action Plan:
- BMI: 20.8 (Normal)
- WHtR: 0.42 (Healthy)
- ABSI Calculation: 0.72 / (20.8^(2/3) × 1.70^(1/2)) ≈ 0.07310
- Interpretation: Riya's ABSI was in the low-risk category, confirming her healthy body composition.
- Action: She focused on maintaining her active lifestyle with aerobics and core strength exercises, monitoring her waist measurement monthly.
Scientific References and Further Reading
Original/Early Paper on ABSI
Krakauer, N. Y., & Krakauer, J. C. (2012). A New Body Shape Index Predicts Mortality Hazard Independently of Body Mass Index. PLOS ONE.
→ View on PubMedSystematic Review Comparing ABSI, BMI, and Waist Circumference
Ji, M. et al. (2018). Effectiveness of A Body Shape Index (ABSI) in predicting all-cause mortality and chronic disease outcomes.
→ View on PubMedABSI and Mortality in People with Type 2 Diabetes
Chen, F. et al. (2025). A Body Shape Index (ABSI) as a risk factor for all-cause mortality among US adults with Type 2 Diabetes.
→ View on PubMedReview of Central Fatness and Mortality
Jayedi, A. et al. (2020). Central fatness and risk of all cause mortality: systematic review and dose-response meta-analysis.
→ View on The BMJ
Frequently Asked Questions
Want to go one step further? Estimate your body fat directly with our RFM Calculator.