STOP-BANG Calculator – Sleep Apnea Risk Screening
Screen for obstructive sleep apnea risk using the validated STOP-BANG questionnaire with instant risk categorization.
Answer all 8 yes/no questions honestly. Each 'Yes' answer scores 1 point. Your total score determines your risk level for obstructive sleep apnea (OSA).
STOP-BANG Calculator – Sleep Apnea Risk Screening
Screen for obstructive sleep apnea risk using the validated STOP-BANG questionnaire with instant risk categorization.
About the STOP-BANG Calculator
The STOP-BANG questionnaire is one of the most widely adopted clinical screening tools for obstructive sleep apnea (OSA), validated in thousands of patients across multiple countries and clinical settings. It was developed by Dr. Frances Chung and colleagues at the University Health Network in Toronto and first published in 2008 in the journal Anesthesiology. The questionnaire derives its name from the eight risk factors it evaluates: Snoring, Tired, Observed apnea, blood Pressure (hypertension), Body mass index (BMI), Age, Neck circumference, and Gender.
Obstructive sleep apnea is a chronic condition in which the upper airway repeatedly collapses during sleep, causing complete or partial cessation of breathing. These apneic episodes fragment sleep, reduce blood oxygen levels, and activate the sympathetic nervous system, resulting in poor sleep quality, excessive daytime sleepiness, morning headaches, and difficulty concentrating. OSA is significantly underdiagnosed: population studies estimate that 80–90% of moderate-to-severe cases in the general population remain unidentified. Left untreated, OSA substantially increases the risk of hypertension, coronary artery disease, atrial fibrillation, stroke, type 2 diabetes, and motor vehicle accidents.
The STOP-BANG questionnaire works by identifying the most common modifiable and non-modifiable risk factors for OSA. Snoring is a cardinal symptom, present in over 90% of OSA patients, caused by vibration of relaxed throat tissues. Daytime tiredness reflects the fragmented, non-restorative sleep produced by repeated arousals. Witnessed apneas — breathing pauses observed by a bed partner — are highly specific for OSA and should prompt urgent evaluation. Hypertension and OSA share a bidirectional relationship: OSA activates sympathetic tone and the renin-angiotensin system, raising blood pressure, while hypertension-related vascular changes can worsen airway dysfunction.
Obesity (BMI > 35) is the most potent modifiable risk factor for OSA, with excess fat deposition around the pharynx narrowing the upper airway. The age threshold of 50 years reflects the progressive decrease in upper airway muscle tone with aging. Neck circumference above 40 cm is a surrogate for the amount of peripharyngeal fat and is one of the strongest anatomical predictors of sleep-disordered breathing. Male sex confers approximately 2–3 times the risk of OSA compared with premenopausal women, though this advantage diminishes substantially after menopause.
The scoring system is elegantly simple: one point for each 'Yes' answer, with total scores ranging from 0 to 8. Scores of 0–2 indicate low probability of moderate-to-severe OSA; 3–4 indicate intermediate probability (roughly 20–40%); and 5–8 indicate high probability (60–80%). The questionnaire has demonstrated sensitivity of 83–100% for detecting moderate-to-severe OSA defined as an apnea-hypopnea index (AHI) of 15 or more events per hour, making it an effective first-line filter before more resource-intensive sleep testing. This calculator is for screening only — a positive result requires formal confirmation with polysomnography or an accredited home sleep apnea test.
STOP-BANG scoring examples
These examples show how different combinations of risk factors translate into scores and risk categories.
| Risk factors present | Score / Risk | Clinical context |
|---|---|---|
| No risk factors (all No) | 0 / Low Risk | Very low probability of OSA. Routine sleep health advice is appropriate. |
| Snoring, Tired, Male (3 Yes answers) | 3 / Intermediate Risk | Moderate probability; lifestyle modifications and healthcare provider discussion recommended. |
| Snoring, Tired, Observed apnea, Hypertension, BMI >35, Age >50 (6 Yes answers) | 6 / High Risk | High probability of moderate-to-severe OSA; formal sleep study strongly recommended. |
| All 8 factors present | 8 / High Risk | Maximum risk score; specialist referral and diagnostic polysomnography warranted without delay. |
How to use the STOP-BANG Calculator
- Read each of the 8 questions carefully and answer honestly based on your current situation.
- For the snoring question, consider feedback from anyone who has slept in the same room. For witnessed apneas, rely on reports from a bed partner or family member.
- For BMI, divide your weight in kg by your height in meters squared; a value above 35 counts as 'Yes'. For neck circumference, measure around the widest part of your neck; above 40 cm (15.7 in) counts as 'Yes'.
- Click 'Calculate STOP-BANG Score' to see your total score (0–8) and your risk category (Low, Intermediate, or High).
- Share your score with your doctor or a sleep specialist to discuss whether a formal sleep study is appropriate for your situation.
STOP-BANG FAQ
What does each letter in STOP-BANG stand for?
STOP-BANG is an acronym: S = Snoring, T = Tired (daytime sleepiness), O = Observed apnea (witnessed breathing pauses), P = Pressure (high blood pressure), B = BMI >35, A = Age >50, N = Neck circumference >40 cm, G = Gender (male). Each factor is associated with an elevated risk of obstructive sleep apnea.
What score indicates high risk for sleep apnea?
A STOP-BANG score of 5 or more indicates high risk for moderate-to-severe obstructive sleep apnea, with a probability of approximately 60–80%. Scores of 3–4 indicate intermediate risk (20–40% probability). Scores of 0–2 indicate low risk. However, even low-risk individuals with bothersome symptoms should speak with their doctor, as the tool is a screening aid, not a definitive diagnostic test.
How is obstructive sleep apnea diagnosed?
The gold standard for diagnosing OSA is polysomnography (PSG), an overnight sleep study conducted in a sleep laboratory that measures brain activity, eye movements, muscle activity, heart rhythm, blood oxygen levels, and breathing effort. Many providers also use home sleep apnea tests (HSATs) for straightforward cases. The STOP-BANG questionnaire helps identify who should be referred for these tests.
What are the treatment options for obstructive sleep apnea?
The most effective treatment for moderate-to-severe OSA is continuous positive airway pressure (CPAP) therapy, which delivers pressurized air through a mask to keep the airway open during sleep. Alternatives include mandibular advancement devices for mild-to-moderate OSA, positional therapy for position-dependent OSA, upper airway surgery, and hypoglossal nerve stimulation for selected patients. Weight loss significantly improves or resolves OSA in overweight patients.
Can the STOP-BANG be used for women?
Yes, but with caveats. The questionnaire was developed and validated primarily in mixed adult populations. Women tend to present with OSA differently — often reporting insomnia, fatigue, and mood disturbance rather than snoring and observed apneas — and may be underscreened. Post-menopausal women have OSA rates comparable to men of similar age. Some clinicians use additional criteria (such as snoring plus either fatigue or observed apnea) to improve sensitivity in women.
Is the STOP-BANG questionnaire used before surgery?
Yes. The STOP-BANG questionnaire is widely used in preoperative settings to identify patients at risk for OSA who may require extra precautions during anesthesia and postoperative monitoring. Patients with undiagnosed OSA are at higher risk for respiratory complications, difficult intubation, and prolonged recovery after general anesthesia. Anesthesiologists use STOP-BANG scores to guide perioperative management decisions.