A step-by-step guide to the WHO fracture risk calculator, walking you through each input and helping you understand your results.
Knowing your bone density is important, but it is only part of the picture. Two people with the same DXA score can have very different fracture risks depending on their age, medical history, and lifestyle. That is where FRAX comes in -- a tool that brings all of these factors together into a personalized fracture risk estimate.
If your doctor has mentioned FRAX, or if you want to understand your own fracture risk more clearly, this article walks you through exactly how it works.
FRAX (Fracture Risk Assessment Tool) is a computer-based algorithm developed by the World Health Organization (WHO) Collaborating Centre at the University of Sheffield, UK. First released in 2008, it has been calibrated for use in over 70 countries and is available in multiple languages.
FRAX calculates two numbers:
It does this by combining your clinical risk factors -- with or without a bone density measurement -- into a single, evidence-based prediction.
You can access FRAX for free at: https://frax.shef.ac.uk/
FRAX helps answer the question: "Based on everything we know about you, how likely is a fracture in the next 10 years?"
The FRAX tool asks for specific information. Here is what each field means:
Select your country of residence. FRAX adjusts its calculations based on the fracture and mortality rates specific to each country, so this is important for accuracy.
Enter your current age. FRAX is validated for adults aged 40-90. Fracture risk increases significantly with age, even independent of bone density.
Select male or female. The calculation differs because women and men have different baseline fracture rates and risk factor profiles.
Enter your weight (in kg or lbs) and height (in cm or inches). FRAX uses these to calculate your BMI. A low BMI (below 20) is an independent risk factor for fracture.
Have you broken a bone after age 40 from a fall from standing height or less (a "fragility fracture")? This includes vertebral compression fractures, even if they were painless and discovered incidentally on X-ray. A previous fracture is one of the strongest predictors of future fracture.
Did either of your parents fracture their hip? Parental hip fracture history is a well-established genetic risk factor for osteoporosis and fracture.
Are you a current smoker? Smoking is directly harmful to bone cells, impairs calcium absorption, and increases fracture risk.
Are you currently taking oral glucocorticoids (such as prednisone or prednisolone), or have you taken them for 3 or more months at a dose of 5 mg per day or more? Long-term glucocorticoid use is one of the most important secondary causes of osteoporosis.
Have you been diagnosed with rheumatoid arthritis (confirmed by a doctor)? RA is an independent risk factor for fracture, beyond any effect of corticosteroid treatment.
Do you have any condition strongly associated with osteoporosis? This includes:
Do you drink 3 or more units of alcohol per day? (One unit is approximately a standard glass of beer, a medium glass of wine, or a single measure of spirits.) Heavy alcohol intake impairs bone formation and increases fall risk.
If you have had a DXA scan, you can enter your femoral neck T-score or BMD value. This makes the prediction more accurate, but FRAX can still provide a useful estimate without it.
You do not need a DXA scan to use FRAX. The tool works with clinical risk factors alone, making it useful as a first step.
After entering your information, FRAX provides two numbers:
This is the percentage chance that you will experience a fracture of the hip, spine (clinical), forearm, or upper arm in the next 10 years. For example, a result of "15%" means that out of 100 people with your exact profile, approximately 15 would be expected to have a major osteoporotic fracture within 10 years.
This is the percentage chance of a hip fracture specifically. Hip fractures are singled out because they have the most severe consequences -- high rates of hospitalization, surgery, disability, and mortality.
These are not certainties -- they are probabilities. A 15% risk does not mean you will definitely fracture; it means that your risk is higher than average and may warrant intervention.
Different countries and guidelines use different FRAX thresholds to decide when treatment should be considered. Here are the most widely used:
Treatment is generally recommended when:
These thresholds were chosen based on cost-effectiveness analyses specific to the US healthcare system.
The UK uses an age-dependent threshold. Rather than fixed percentages, NOGG compares your FRAX score to the average fracture risk of someone your age who has already had a fracture. If your risk exceeds that threshold, treatment is recommended. This approach accounts for the fact that "normal" fracture risk varies significantly by age.
NOGG provides a traffic-light system:
Australian guidelines incorporate FRAX alongside clinical judgment, with treatment generally considered when FRAX indicates elevated risk, particularly in combination with a T-score of -2.5 or below.
Regardless of which country's thresholds are used, the core idea is the same: FRAX helps identify people whose fracture risk is high enough that the benefits of treatment clearly outweigh the risks.
Treatment thresholds are guidelines, not rigid rules. Your doctor will consider your FRAX results alongside your preferences, overall health, and other factors.
Meet Margaret, a 68-year-old woman from the United States:
Her FRAX results:
Both values exceed the NOF treatment thresholds (20% major, 3% hip). Based on these results, Margaret's doctor would likely recommend starting osteoporosis treatment in addition to lifestyle measures, even though her DXA T-score is in the osteopenia range rather than osteoporosis.
This illustrates an important point: FRAX can identify people who need treatment even when their bone density alone would not qualify them.
FRAX is a valuable tool, but like all tools, it has limitations:
FRAX records risk factors as yes/no. It does not account for:
In reality, these dose-response relationships matter. Your doctor can make clinical adjustments when the simple yes/no does not capture the full picture.
FRAX does not include fall risk as a variable, despite falls being the proximate cause of most fractures (except vertebral compression fractures). If you have a high fall risk -- due to balance problems, medication side effects, poor vision, or environmental hazards -- your actual fracture risk may be higher than FRAX estimates.
FRAX uses the femoral neck BMD only, not the lumbar spine. In some individuals, the spine T-score is significantly lower than the hip, and FRAX may underestimate their risk.
FRAX is designed for untreated individuals. If you are already taking osteoporosis medication, your FRAX score would underestimate your "untreated" risk.
FRAX is validated for ages 40-90. It should not be used for younger adults or for individuals over 90.
FRAX is an excellent starting point, but clinical judgment remains essential. Your doctor may adjust treatment decisions based on factors FRAX does not capture.
Q. Can I use FRAX on my own, or does my doctor need to do it?
You can access the FRAX calculator yourself at https://frax.shef.ac.uk/ and enter your information. However, interpreting the results and making treatment decisions should be done with your doctor, who can consider additional factors and explain what the numbers mean for your specific situation.
Q. I do not have a DXA scan result. Can I still use FRAX?
Yes. FRAX can calculate your fracture risk using clinical risk factors alone, without a BMD value. The result is slightly less precise, but still clinically useful. In fact, many guidelines recommend using FRAX as a first step to determine whether a DXA scan is needed.
Q. My FRAX score is below the treatment threshold. Does that mean I am safe?
A below-threshold FRAX score means your fracture risk is relatively low over the next 10 years, which is reassuring. However, risk factors can change over time (for example, if you start glucocorticoids, have a fracture, or develop a new medical condition). Periodic reassessment is sensible, particularly after age-related milestones or new health developments.
Q. Does FRAX work for men?
Yes. FRAX is validated for both men and women. While osteoporosis is more common in women, FRAX can identify men at elevated fracture risk and guide treatment decisions.
Q. My doctor calculated my FRAX score and it was borderline. What happens next?
If your FRAX score is near the treatment threshold, your doctor may recommend:
Q. Is FRAX the only fracture risk assessment tool?
FRAX is the most widely used and validated tool globally, but others exist. In the UK, QFracture is an alternative that includes additional variables (such as falls and some medications). The Garvan Fracture Risk Calculator from Australia also incorporates fall history and number of prior fractures. Your doctor will use the tool most appropriate for your region and clinical situation.
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Medical Supervision
Hiroyuki Katoh（Orthopedic Surgeon, Medical Registration No. 409723）
Tokai University Hospital / Shoyo Kashiwadai Hospital
Last updated:March 21, 2026
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