FRAX Calculator UK: How to Use It and What It Asks

What is the FRAX calculator?

FRAX is a tool that turns a handful of facts about you into a percentage: your probability of breaking a bone in the next 10 years.

It was, in its own description, "developed to evaluate fracture risk", and it works by integrating "the risks associated with clinical risk factors as well as bone mineral density (BMD) at the femoral neck." The underlying models "have been developed from studying population-based cohorts from Europe, North America, Asia and Australia" — the work is credited to Osteoporosis Research Ltd and associated with the University of Sheffield. FRAX / FRAXplus, Osteoporosis Research Ltd

One practical note before you go looking for it: the calculator is now reached at fraxplus.org. The older University of Sheffield web addresses redirect there, so an old bookmark will still land you in the right place.

What does the FRAX calculator ask you?

A short set of clinical risk factors — the things that shift fracture risk most, and that a person can actually answer.

The Royal Osteoporosis Society describes a fracture risk assessment as one that "takes all the different risk factors for broken bones that you may have into account", and lists them as including: Royal Osteoporosis Society

• being aged 50 or over
• experiencing menopause
• having low bone density
• breaking a bone easily
• certain medicines
• certain health conditions
• certain lifestyle factors
• your family history

On top of those, FRAX is designed to take bone mineral density at the femoral neck — the top of the thigh bone — when a scan result is available. FRAX / FRAXplus

Two of those bullet points are worth pausing on, because they are where people most often under-report themselves. "Breaking a bone easily" means a fracture from something that shouldn't have caused one — a fall from standing height, a knock. And "certain medicines" most commonly means long-term oral steroids, which is why we cover it separately in steroids and bone loss.

What do the results mean?

You get two percentages, and they answer two different questions.

FRAX returns "the 10-year probability of hip fracture and the 10-year probability of a major osteoporotic fracture (clinical spine, forearm, hip or shoulder fracture)." FRAX / FRAXplus

The number	What it covers
10-year major osteoporotic fracture risk	Clinical spine, forearm, hip or shoulder
10-year hip fracture risk	The hip specifically — reported separately because of its consequences

The Royal Osteoporosis Society frames the output the same way: the assessment "uses your answers to calculate your risk of breaking a bone in the next 10 years", and "The result of your assessment is given as a percentage, which shows the probability of you breaking a bone in the next 10 years." Royal Osteoporosis Society

A percentage is a population statement applied to you, not a forecast of an event. A 10-year major fracture risk of 12% does not mean something will happen; it means that of a large group of people with your profile, roughly twelve in a hundred would sustain such a fracture over a decade. What the number is genuinely good for is deciding whether to act — and that decision layer is covered in fracture risk and FRAX explained.

Do you need a bone density scan to use FRAX?

No — but the answer is sharper with one.

FRAX can be run without a bone density value, and "Several simplified paper versions, based on the number of risk factors are also available." FRAX / FRAXplus That is deliberate: it makes the tool usable in a GP appointment, anywhere in the world, with no equipment.

But the tool's own description is that it integrates clinical risk factors as well as bone mineral density at the femoral neck — the density value is part of the design, not an optional extra bolted on. And the Royal Osteoporosis Society notes that as part of an assessment, "If you haven't already, you may also be referred for a bone density scan." Royal Osteoporosis Society

The distinction is simple enough to hold onto:

• FRAX without a scan estimates your risk from your circumstances.
• FRAX with a scan estimates your risk from your circumstances and the actual state of your bone.

If you want to understand what that density measurement itself reports, see DEXA scan results and T-scores explained, and REMS vs DEXA for the radiation-free route to the same measurement.

FRAX or QFracture?

Both are in UK use. The Royal Osteoporosis Society names them together: you "may also hear these test being referred to as a FRAX® or QFracture® test, which are the tools doctors can use to complete the assessment." Royal Osteoporosis Society

They ask overlapping questions and both express the result as a 10-year percentage. Which one you encounter depends on your clinician and their system rather than on anything about you.