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Fatty Liver Index (FLI) Calculator

Calculate your Fatty Liver Index (FLI) to screen for non-alcoholic fatty liver disease (NAFLD) or metabolic dysfunction-associated fatty liver disease (MAFLD). This clinically validated tool uses triglycerides, BMI, Gamma-glutamyl transferase (GGT), and waist circumference to estimate the likelihood of hepatic steatosis. Enter your lab results to track your liver health and metabolic risk.

Enter Values

Triglycerides

Fasting blood triglycerides

TG Unit

mg/dL is standard in US; mmol/L in UK, Canada, Australia

Body Mass Index (BMI)

1070

Weight in kg divided by height in meters squared

GGT (U/L)

Gamma-glutamyl transferase, a liver enzyme

Waist Circumference

Measure at the level of the navel

Waist Unit

Result

Enter values above and click Calculate to see your result.

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Formula

Core Formula

L = 0.953 \times \ln(\text{TG}) + 0.139 \times \text{BMI} + 0.718 \times \ln(\text{GGT}) + 0.053 \times \text{WC} - 15.745 \\ \text{FLI} = \frac{e^L}{1 + e^L} \times 100

How it works: The Fatty Liver Index (FLI) is a predictive model developed by Bedogni et al. in 2006. It combines four common markers: triglycerides (a measure of blood fats), Body Mass Index (BMI), GGT (a liver enzyme), and waist circumference (a measure of central obesity). The natural logarithm (ln) of TG and GGT is used to account for their statistical distribution. The result is a percentage score from 0 to 100, where higher scores indicate a greater probability of having a fatty liver.

Worked Example

A 45-year-old male with Triglycerides of 155 mg/dL, BMI of 28, GGT of 35 U/L, and a waist circumference of 96 cm:

1Step 1: Identify values: TG = 155, BMI = 28, GGT = 35, WC = 96

2Step 2: Calculate L coefficient: 0.953 x ln(155) + 0.139 x 28 + 0.718 x ln(35) + 0.053 x 96 - 15.745

3Step 3: L = (0.953 x 5.04) + 3.89 + (0.718 x 3.56) + 5.09 - 15.745 = 0.58

4Step 4: Calculate FLI: (e^0.58 / (1 + e^0.58)) x 100 = (1.786 / 2.786) x 100 = 64.1

5Step 5: Interpretation: 64.1 is in the High Risk category (>= 60), indicating hepatic steatosis is likely.

Understanding the Fatty Liver Index (FLI)

The Fatty Liver Index is a simple, non-invasive algorithm used by healthcare professionals and individuals to screen for non-alcoholic fatty liver disease (NAFLD), recently renamed to metabolic dysfunction-associated fatty liver disease (MAFLD). It is highly accurate in predicting hepatic steatosis in the general population.

Clinically validated: The index was developed by studying patients with and without fatty liver confirmed by abdominal ultrasound
Screening utility: An FLI score below 30 effectively rules out fatty liver in most individuals (91% sensitivity)
Risk assessment: A score above 60 suggests a high probability of having a fatty liver and warrants further medical consultation
Metabolic markers: It uses four measurements that reflect metabolic syndrome: abdominal obesity, high triglycerides, high BMI, and elevated liver enzymes
Silent epidemic: NAFLD affects up to 25% of the global population and is often asymptomatic in its early stages

Consult with your doctor to interpret these results in the context of your overall health. Early detection allows for lifestyle changes that can reverse fatty liver.

You can also calculate changes using our Lipid Accumulation Product (LAP) Index Calculator, BMI Calculator, Waist-to-Height Ratio Calculator, Body Fat Calculator or Biological Age Calculator (PhenoAge).

FLI Score Risk Interpretation

Clinical risk tiers for hepatic steatosis based on the Fatty Liver Index score.

FLI Score	Risk Category	Likelihood of Fatty Liver
Below 30	Low Risk	Fatty liver ruled out (high certainty)
30 to 59	Intermediate	Indeterminate result, monitoring required
60 and Above	High Risk	Fatty liver ruled in (high probability)

Note: Interpretation based on Bedogni et al. (2006). A score of 60+ has a positive likelihood ratio of 4.3 for hepatic steatosis.

Frequently Asked Questions

What is the Fatty Liver Index (FLI)?

The Fatty Liver Index is a validated algorithm used to predict the presence of fatty liver (hepatic steatosis). It uses four parameters: Body Mass Index (BMI), waist circumference, triglycerides, and gamma-glutamyl transferase (GGT).

How accurate is the FLI?

FLI is highly accurate for screening. A score < 30 has a negative likelihood ratio of 0.2 (ruling out fatty liver in 91% of cases), while a score >= 60 has a positive likelihood ratio of 4.3 (indicating a high probability of fatty liver).

What do the FLI scores mean?

Scores are from 0 to 100. < 30 is Low Risk (fatty liver unlikely); 30-59 is Intermediate Risk; >= 60 is High Risk (fatty liver likely). If your score is high, you should discuss the results with a healthcare provider for further evaluation, such as an ultrasound.

Can I lower my FLI score?

Yes. Since FLI depends on weight, waist circumference, and triglycerides, lifestyle interventions like weight loss, regular exercise, and a healthy diet (reducing sugar and alcohol) can significantly lower your score and even reverse fatty liver in early stages.

Is FLI the same as a liver biopsy?

No. A liver biopsy is the "gold standard" for diagnosing liver disease but is invasive. FLI is a non-invasive screening tool. An ultrasound or FibroScan is often the next step if an FLI score is high.

Can I embed this Fatty Liver Index (FLI) Calculator on my website?

Yes. Click the "Embed" button at the top of this page to customize the size, colors, and theme, then copy the iframe code. Paste it into any HTML page, WordPress site, or CMS. It is completely free, requires no signup, and works on all devices. You can also visit our embed guide at calculory.com/services/embed-calculators for more details.

Medical Disclaimer

This calculator is provided for informational and educational purposes only. It is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making any decisions based on these results. Do not disregard or delay seeking medical advice because of information obtained from this tool.

AI Assistant

Ask about this calculator

I can help you understand the fatty liver index (fli) calculator formula, interpret your results, and answer follow-up questions.

Try asking

Our AI assistant provides general estimates and advice only. Please consult a qualified healthcare professional before making any health-related decisions.

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Lipid Accumulation Product (LAP) Index Calculator BMI Calculator Waist-to-Height Ratio Calculator Body Fat Calculator Biological Age Calculator (PhenoAge)

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