What SurgCalc is
SurgCalc is a suite of free, ad-free surgical prediction tools for clinicians and informed readers. Each calculator implements a statistical model derived from large national clinical registries — including ACS-NSQIP and MBSAQIP — and is published with its model version, data source, validation performance, and limitations. All calculations run locally in your browser; no patient data is collected or transmitted.
SurgCalc is published by Abigail MD, Inc. and is not affiliated with, or endorsed by, the American College of Surgeons or the registries whose de-identified public-use files inform the models.
Who builds this
SurgCalc is authored and maintained by Ramsey M. Dallal, MD, a bariatric and general surgeon in the Department of Surgery, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA. Dr. Dallal is the lead author of the peer-reviewed prediction models that power these calculators (publications on PubMed).
Site content prepared and reviewed by Ramsey M. Dallal, MD. Last reviewed: July 2026.
Evidence policy
- Every calculator is based on a defined statistical model with a locked, versioned coefficient set; the model version and data source are shown on each page.
- Models are validated (including temporal validation on held-out years where available) before deployment, and performance metrics are disclosed.
- Reference and guidance content is synthesized from published guidelines and trials, cited on the page where it appears.
- Corrections: if you find an error, use the contact form. Material model changes are versioned and dated.
- Outputs are population-level statistical estimates for decision support — not medical advice, and not a substitute for clinical judgment. See Terms.
Peer-reviewed publications behind the calculators
- Dallal RM, Riggio J, Li M, Eraso LH, Moran B, Merli GJ. Targeting Extended Thromboprophylaxis after Surgery Through Multidimensional Dynamic Pulmonary Embolism Risk Assessment: Development and Temporal Validation in 4.8 Million Operations. J Am Coll Surg. 2026. PMID: 42319019 · DOI
- Dallal RM, Neff M, Beekley AC, Dougherty M, Leighton J. Dynamic Reassessment of Pulmonary Embolism Risk after Metabolic-Bariatric Surgery. J Am Coll Surg. 2026. PMID: 42228460 · DOI
- Dallal RM, Neff MA, Tatarian T, Harrison TD. Percentile-based weight loss benchmarks after sleeve gastrectomy, Roux-en-Y gastric bypass, and duodenal switch: a multi-site cohort study. Surg Obes Relat Dis. 2026 (accepted, in press).
Independence
SurgCalc carries no advertising, no sponsorships, and no industry funding. There are no accounts, no cookies, and no analytics trackers — see the Privacy Policy.