FRAX Score Calculator
WHO 10-Year Fracture Risk Assessment
Patient Demographics
Age & sex for risk calculation
Clinical Risk Factors
Select all that apply
Risk Profile
Risk Factors Endorsed0
Patient Age—
Sexfemale
Guidelines & Evidence
Verified
Last Review: 2026-07-17
When to Use
When to Use
Postmenopausal women age 40-90 with osteopenia or risk factors
Men age 50-90 with clinical risk factors for osteoporosis
Treatment-naïve patients being considered for bisphosphonate therapy
Patients with prior fragility fracture (hip, spine, wrist, humerus)
Routine osteoporosis screening in high-risk populations
Monitoring fracture risk in patients with secondary osteoporosis
Contraindications
Patients already on active osteoporosis treatment (use FRAX with T-score)
Age under 40 — not validated for younger populations
Patients with known osteomalacia or Paget disease of bone
How it Works
Formula
10-year fracture probability is computed from a meta-analysis of 12 multinational cohorts
Inputs: age, sex, BMI, prior fracture, parent hip fracture, smoking, glucocorticoids, RA, secondary osteoporosis, alcohol
Femoral neck BMD (T-score) can optionally be entered for refined risk estimation
The algorithm yields two outputs: Hip Fracture Probability and Major Osteoporotic Fracture Probability
Scoring Components
| Risk Factor | Weight | Notes |
|---|---|---|
| Age | Continuous | Exponential increase per decade |
| Prior fragility fracture | OR 1.85 | Especially hip, spine, wrist |
| Parent hip fracture | OR 2.3 | Maternal history stronger |
| Current smoking | OR 1.84 | Dose-dependent risk |
| Glucocorticoid use | OR 2.25 | ≥5 mg prednisolone/day ≥3 months |
| Rheumatoid arthritis | OR 1.95 | Independent of steroid use |
| Secondary osteoporosis | OR 1.5-2.0 | DM, hyperthyroidism, IBD, etc. |
| Alcohol ≥3 units/day | OR 1.68 | Threshold effect noted |
Clinical Pearls
Key Considerations
FRAX does NOT account for dose or duration of glucocorticoid exposure — this may underestimate risk
Prior vertebral fracture is the single strongest predictor of future fractures (OR 4.4)
FRAX without BMD still provides useful risk stratification in most patients
The treatment thresholds (hip ≥3% or major ≥20%) are NOF guidelines; regional variations exist
FRAX may underestimate risk in patients with multiple falls, frailty, or diabetes
Re-calculation is recommended every 2 years or after any change in risk factor status
Common Pitfalls
Do not use FRAX to monitor treatment response — it is not designed for serial measurements
BMI entered in kg/m²; calculating incorrectly will shift risk estimates
The "secondary osteoporosis" box excludes RA and medication causes already accounted for
Next Steps
Clinical Actions
01
Review absolute fracture probability and compare to regional treatment thresholds
02
If above threshold: initiate pharmacotherapy (bisphosphonate, denosumab, or anabolic agent)
03
If below threshold: recommend lifestyle optimization, calcium (1200 mg/day) and vitamin D (800 IU/day)
04
Re-assess fracture risk every 1-2 years or when clinical status changes
05
Consider DXA scan if not already performed for baseline BMD measurement
06
Evaluate and treat secondary causes of osteoporosis if present
The Evidence
Primary References
FRAX and the assessment of fracture probability in men and women from the UK
Kanis JA et al. • Osteoporosis International. 2008;19(4):385-397 — Derivation and validation of the FRAX algorithm
The use of clinical risk factors enhances the performance of BMD in the prediction of hip and osteoporotic fractures in men and women
Kanis JA et al. • Osteoporosis International. 2007;18(8):1033-1046 — Landmark meta-analysis underpinning FRAX
Validation Studies
Validated in 64+ countries with country-specific adjustment factors
AUC for hip fracture prediction: 0.75-0.85 across multiple validation cohorts
FRAX calibration demonstrated in US, UK, Swedish, Japanese, and Chinese populations
Origins & History
Development
The FRAX tool was developed by Professor John Kanis and the WHO Collaborating Centre for Metabolic Bone Diseases at the University of Sheffield, UK. It was first released in 2008 and has since been adopted globally as the standard for fracture risk assessment.
Last Comprehensive Review: 2026-07-17