Medical Calculators
Clinical reference calculators with the formulas, reference ranges and limitations behind each score. Built for healthcare professionals and students — not for self-diagnosis.
All Medical Calculators
Anion Gap Calculator
Serum anion gap from sodium, chloride and bicarbonate, with the albumin-corrected value and the causes of high, normal and low results.
CHA₂DS₂-VASc Score
Stroke-risk score for non-valvular atrial fibrillation, with the sex-adjusted thresholds guidelines use for anticoagulation decisions.
Child-Pugh Score
Severity classification for cirrhosis from bilirubin, albumin, INR, ascites and encephalopathy, with prognostic context.
eGFR Calculator (CKD-EPI 2021)
Race-free kidney function estimate with KDIGO G1–G5 staging and mg/dL or µmol/L input.
LDL Cholesterol Calculator
Friedewald LDL-C plus non-HDL cholesterol, in mg/dL or mmol/L.
HAS-BLED Score
Bleeding-risk score for anticoagulation, with the modifiable factors listed.
Corrected Calcium Calculator
Albumin-adjusted calcium in mg/dL or mmol/L, with reference ranges.
HbA1c to eAG Calculator
Convert HbA1c into estimated average glucose, with DCCT and IFCC units.
MELD Score Calculator
MELD and MELD-Na with the UNOS floor and cap rules.
Wells Score (DVT / PE)
Clinical probability of deep vein thrombosis or pulmonary embolism.
Corrected Sodium Calculator
Katz and Hillier corrections for sodium in hyperglycaemia.
Glasgow Coma Scale (GCS)
Eye, verbal and motor scoring with E V M notation and the pupil-adjusted GCS-P.
PERC Rule
Eight criteria that can exclude pulmonary embolism without testing.
Anion Gap Delta Ratio
Detect mixed metabolic acidosis and alkalosis from the delta-delta.
Ionised Calcium (pH-corrected)
Adjust ionised calcium to pH 7.40, in mmol/L or mg/dL.
PHQ-9 Depression Questionnaire
Nine-item depression screening with severity bands and item 9 safety guidance.
GAD-7 Anxiety Questionnaire
Seven-item anxiety screening with severity bands and the 10-point cut-off.
CURB-65 Score
Pneumonia severity and admission decision from five criteria.
HEART Score
Chest pain risk score with six-week MACE estimates.
How to Use These Calculators
Each calculator takes the values you already have from a laboratory report or bedside assessment and returns the score with its interpretation. Results update as you type or change a selection, so you can see how a single parameter shifts the total.
- Anion gap — enter sodium, chloride and bicarbonate; add albumin to see the corrected gap, which is the more reliable number whenever albumin is low.
- CHA₂DS₂-VASc — tick the risk factors present and choose the age band; the tool applies the guideline thresholds separately for men and women.
- Child-Pugh — select the band that matches each of the five parameters; the total maps to class A, B or C.
Reference Ranges Vary — Check Your Laboratory
Cut-offs differ slightly between laboratories, analysers and guidelines. The anion gap in particular is quoted as 8–12 mEq/L in some centres and 3–11 in others, and Child-Pugh thresholds vary between the original Child-Turcotte criteria and Pugh’s 1973 modification. The interpretation shown here follows widely cited values, but your local reference range always takes precedence.
Frequently Asked Questions
Who are these medical calculators for?
Healthcare professionals and students who need a quick check of a score they already understand. They are deliberately documented with formulas and limitations so the output can be interpreted correctly.
Can I use them to work out my own risk?
They are not designed for that. Scores such as CHA₂DS₂-VASc and Child-Pugh summarise clinical findings that only a clinician can verify, and treatment decisions depend on much more than a number.
Is any data sent anywhere?
No. Every calculation runs in your browser; nothing you enter is transmitted or stored.