Centor Score (Modified McIsaac) calculator
Result
0points
~1–3% GAS — no test, no antibiotics
How to use it
- 1
Four clinical criteria + age. Exudate, lymphadenopathy, fever, no cough — each 1 pt.
- 2
Age modifier (McIsaac). Children 3–14: +1. Adults 45+: −1.
- 3
Score ≤1. GAS probability very low — antibiotics NOT indicated. No swab needed.
When to use it
- Sore throat in primary care
- Score ≥3 + positive rapid antigen test: treat with penicillin 10 days (or amoxicillin).
- Antibiotic stewardship
- Score ≤1: 95%+ chance NOT GAS — treat symptomatically. Reduces unnecessary antibiotics.
- Quinsy threshold
- Peritonsillar abscess: Centor not validated — ENT referral regardless of score.
A reference for clinicians and students, not medical advice. A score supports a decision; it does not make one. Check every result against the patient in front of you and your local protocol.
At a glance
- Specialty
- Infectious diseases
- Inputs
- 5
- Type
- Points score
