Alvarado Score Calculator
Estimate the likelihood of acute appendicitis with the Alvarado score (mnemonic MANTRELS), a 10-point clinical score from symptoms, signs and two blood-test findings. It helps decide who can be safely discharged, who needs observation or imaging, and who is likely to need surgery. Tick the features that are present to get the score and its interpretation.
About the Alvarado score
The Alvarado score risk-stratifies suspected acute appendicitis from readily available clinical and laboratory findings. Source: Alvarado A, “A practical score for the early diagnosis of acute appendicitis,” Annals of Emergency Medicine 1986;15(5):557–564.
Frequently asked questions
What makes up the Alvarado score?
The Alvarado score is made up of eight items, worth ten points in total (mnemonic MANTRELS): Migration of pain to the right lower quadrant (1), Anorexia (1), Nausea or vomiting (1), Tenderness in the right lower quadrant (2), Rebound tenderness (1), Elevated temperature ≥ 37.3 °C (1), Leukocytosis with a white-cell count over 10 × 10⁹/L (2), and a Shift of the white cells to the left, neutrophils over 75% (1). The two most weighted items are right-lower-quadrant tenderness and leukocytosis. Every item is either a bedside finding or a routine full blood count result, so the score can be completed at first assessment without imaging. Ticking all eight boxes in this calculator gives the maximum of 10 points.
How is the score interpreted?
A common reading of the Alvarado score is: 1–4 makes appendicitis unlikely (a cut-off of 5 is good at ruling it out); 5–6 is compatible with appendicitis and usually prompts observation or imaging; 7–8 is probable; and 9–10 is very probable, favouring surgical assessment. Local pathways vary, and imaging (ultrasound or CT) is often used in the middle range. The bands come from Alvarado’s original 1986 paper, which derived the score from a retrospective review of 305 patients admitted with abdominal pain suggestive of appendicitis. The score is stronger at excluding appendicitis at the low end than at confirming it at the high end, so a high score prompts surgical assessment rather than replacing it.
Is the score used the same way in everyone?
Not exactly — the Alvarado score performs less well in women of reproductive age, where gynaecological causes mimic appendicitis. Accuracy is also lower in children, for whom paediatric scores such as the Pediatric Appendicitis Score exist. It is a decision aid to be combined with clinical judgement and, where needed, imaging — not a stand-alone diagnosis.
What is a modified Alvarado score?
The modified Alvarado score drops the “shift to the left” item, giving a maximum of 9, because the differential white-cell count is not always available. This calculator uses the original 10-point Alvarado score; leave the left-shift box unticked if you do not have that result. Totals from the two versions are not interchangeable: a patient with a left shift scores one point higher on the original 10-point scale than on the 9-point modified one. The two-point leukocytosis item is kept in both versions, so a white-cell count is still needed either way.
What should I do with a high score?
A high score raises the probability of appendicitis and typically prompts surgical review and consideration of appendicectomy or confirmatory imaging, alongside pain relief and fluids. A low score, with a reassuring examination, may allow discharge with safety-netting. This calculator is an educational reference, not medical advice.
This is a reference tool, not a diagnosis or medical advice. Results depend on the laboratory, assay and clinical context, and reference intervals vary between labs and by age and sex — always read your result against the range printed on your own report and discuss it with a qualified healthcare professional.
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