The ACS NSQIP Surgical Risk Calculator is an online tool developed by the American College of Surgeons (ACS) that estimates a patient’s individual risk of postoperative complications and mortality for a huge range of surgical procedures. It’s based on data from the National Surgical Quality Improvement Program (NSQIP), a large, prospectively collected clinical registry.
The real calculator is available on the ACS website and in their mobile app, and uses complex logistic regression models built from millions of operations across hundreds of hospitals. It is intended to support shared decision-making, informed consent, and perioperative planning, not to replace clinical judgment or local guidelines. PMC+2PLOS+2
How the ACS NSQIP Surgical Risk Calculator works (conceptually)
For a given case, the user enters:
- Procedure (CPT code or textual pick list)
- Demographics – age, sex, height, weight/BMI
- Comorbidities – e.g. diabetes, COPD, CHF, dialysis, ascites, steroid use, sepsis, etc.
- Functional status – independent vs partially/totally dependent
- ASA class
- Emergency vs elective status
- ± Procedure-specific variables (e.g. if it’s a cancer operation)
Using these inputs, NSQIP computes predicted risks of multiple outcomes, such as:
- Serious complication
- Any complication
- Pneumonia, cardiac complication, renal failure
- Surgical site infection (superficial, deep, organ/space)
- Return to operating room
- Venous thromboembolism
- Death
- Discharge to nursing/rehab facility
These are calculated using proprietary, procedure-specific models that are regularly recalibrated using NSQIP data. PLOS+2CORE+2
Limitations and appropriate use
- The underlying regression models and coefficients are proprietary to ACS.
- The calculator is intended to complement, not replace, clinical judgment.
- Accuracy depends on appropriate case selection, variable entry, and population similarity to the NSQIP cohort.
- It’s validated for many common surgeries, but may be less accurate in highly specialized or rare procedures. PLOS+2ScienceDirect+2
Because the ACS models are proprietary, we cannot replicate the true NSQIP calculator logic or coefficients here.
The HTML tool below is an educational, NSQIP-inspired generic risk score, not the official ACS NSQIP calculator.
NSQIP-Inspired Surgical Risk Estimator
Educational tool to approximate perioperative risk using common NSQIP-style predictors
This is not the official ACS NSQIP Surgical Risk Calculator and does not use NSQIP’s proprietary models or coefficients. It is an educational, simplified risk score for use by health professionals as a teaching and rough stratification aid only. For real patient counselling and documentation, please use the official ACS NSQIP calculator and your institution’s guidelines.
Enter patient and procedure details
Total risk points: –
Overall unfavorable outcome risk band: Not yet calculated
Approximate chance of an unfavorable outcome: –
Enter the details above and click “Estimate risk” to see a simplified educational risk score and approximate risk band inspired by NSQIP-style predictors.
This tool uses a simple, arbitrary point system loosely reflecting how factors such as age, ASA class, functional dependence, emergency status, and major comorbidities increase postoperative risk. It is not calibrated to NSQIP data and is not a substitute for the official ACS NSQIP Surgical Risk Calculator. Always use institutional tools and guidelines for real-world decisions.
