Radcalcs is a free collection of evidence-based clinical calculators built for physicians and radiologists. Every tool is grounded in published guidelines and designed for real clinical workflows — fast, mobile-optimized, and free from clutter.
Clinical decision support tools should be free, fast, and accurate. Radcalcs exists because the best clinical calculators online are often slow, cluttered with ads, or built on outdated equations. We are building the resource we wished existed during training and clinical practice.
All calculations are performed in your browser. No patient data is ever transmitted to our servers — period.
Every calculator cites the source guideline (KDIGO, ACR, ICRP, PI-RADS v2.1, CMS).
Designed for one-handed use on rounds. No pinch-zoom required.
Results update as you type. No submit buttons, no loading states.
All math runs in your browser. Zero patient data leaves your device.
Medical calculation tools carry real responsibility. An error in a formula implementation — even a small one — can affect clinical decisions. Our accuracy process is systematic and documented:
Radcalcs is designed for licensed healthcare professionals and trainees working under supervision. Our primary audience includes:
Important: Radcalcs is not intended as a substitute for clinical judgment, formal medical advice, or direct patient evaluation. All outputs must be interpreted by a qualified healthcare professional in the context of the full clinical picture. Do not use this site to make clinical decisions without appropriate clinical training and supervision.
Radcalcs currently provides the following clinical calculators, organized by specialty domain:
Estimates glomerular filtration rate using the race-free CKD-EPI 2021 creatinine equation. Outputs CKD stage classification and risk category per KDIGO 2022 guidelines. Accepts serum creatinine in mg/dL or µmol/L.
Calculates total kidney volume (TKV) and height-adjusted TKV (HtTKV) from ultrasound or MRI measurements. Used in ADPKD staging and prognostication per Mayo Clinic Image Class criteria.
ACR Thyroid Imaging Reporting and Data System (TI-RADS) scoring for thyroid nodules on ultrasound. Scores composition, echogenicity, shape, margin, and echogenic foci. Outputs TI-RADS level (TR1–TR5) with ACR-recommended FNA and follow-up size thresholds.
PI-RADS v2.1 assessment categories for prostate MRI. Guides clinically significant cancer suspicion scoring for peripheral zone (PZ) and transition zone (TZ) lesions using T2-weighted, DWI, and DCE sequences. Outputs PI-RADS category 1–5 with biopsy guidance.
ACR Breast Imaging Reporting and Data System (BI-RADS) category reference for mammography, ultrasound, and MRI. Summarizes malignancy risk estimates and management recommendations for categories 0–6.
Computes the Agatston coronary artery calcium (CAC) score from CT measurements and provides percentile-based risk classification by age and sex. Incorporates ACC/AHA 2019 guidance on CAC-guided statin decision-making.
2017 Fleischner Society guidelines for management of incidentally detected pulmonary nodules in adults. Provides follow-up recommendations based on nodule size, morphology (solid vs. subsolid), and patient risk factors.
Converts CT dose length product (DLP) to estimated effective dose in millisieverts (mSv) using ICRP 103 tissue weighting factors and body-region conversion coefficients. Includes ACR Dose Index Registry benchmark comparison by exam type.
Radiology CPT code lookup with 2024 CMS work RVU values. Supports multi-code entry for daily or monthly productivity totaling, with annualized projection. Useful for tracking radiologist productivity against MGMA benchmarks.
HEART score for early risk stratification of chest pain in the emergency department. Scores History, ECG, Age, Risk factors, and Troponin. Outputs risk category (low/moderate/high) with associated 6-week MACE event rates.
CHA2DS2-VASc stroke risk score for patients with non-valvular atrial fibrillation. Scores Congestive heart failure, Hypertension, Age, Diabetes, prior Stroke/TIA, Vascular disease, and Sex. Outputs annual stroke risk estimate with anticoagulation guidance per current AF guidelines.
10-year atherosclerotic cardiovascular disease (ASCVD) risk calculator using the ACC/AHA 2013 Pooled Cohort Equations. Inputs include age, sex, race, cholesterol, blood pressure, diabetes status, and smoking. Guides statin therapy decisions per ACC/AHA 2019 cholesterol guidelines.
Wells clinical prediction rule for pre-test probability of pulmonary embolism. Stratifies patients into low, moderate, or high pre-test probability to guide D-dimer ordering and CT pulmonary angiography decisions.
Wells clinical prediction rule for pre-test probability of deep vein thrombosis. Scores clinical features and risk factors to stratify patients into low, moderate, or high DVT probability to guide ultrasound and D-dimer testing.
CURB-65 severity score for community-acquired pneumonia. Scores Confusion, Urea, Respiratory rate, Blood pressure, and age 65 or older. Outputs mortality risk estimate with hospitalization and ICU guidance per BTS guidelines.
Pneumonia Severity Index (PSI) for risk stratification of community-acquired pneumonia. Assigns patients to risk classes I–V based on demographics, comorbidities, physical examination findings, and laboratory values. Guides outpatient vs. inpatient vs. ICU care decisions.
Model for End-Stage Liver Disease (MELD) and MELD-Na scores. Calculates 90-day mortality risk in patients with chronic liver disease. Used by UNOS for liver transplant allocation prioritization. Inputs include creatinine, bilirubin, INR, and sodium.
Child-Pugh score for assessment of cirrhosis severity and prognosis. Scores bilirubin, albumin, INR/prothrombin time, ascites, and hepatic encephalopathy. Outputs Child-Pugh class A, B, or C with associated 1- and 2-year survival estimates.
Estimates total liver volume from cross-sectional imaging measurements. Used in pre-operative planning for hepatic resection, transplant evaluation, and monitoring of hepatic pathology. Includes reference ranges by height and body surface area.
Estimates spleen volume from ultrasound or CT measurements using the ellipsoidal formula (length × width × depth × 0.524). Provides reference ranges for splenomegaly classification.
Calculates ovarian volume from ultrasound measurements. Provides reference ranges for reproductive-age women, postmenopausal women, and girls by age. Used in evaluation of ovarian pathology and polycystic ovary syndrome assessment.
Calculates testicular volume using both the Lambert formula (length × width × depth × 0.71) and the ellipsoidal formula. Provides age-referenced normal ranges for use in male reproductive health assessment and evaluation of testicular pathology.
Estimates uterine volume from ultrasound dimensions. Provides reference ranges by reproductive status (nulliparous, parous, postmenopausal). Used in evaluation of uterine size for fibroid burden, endometrial pathology, and procedural planning.
Body Mass Index calculator supporting metric and imperial units. Outputs WHO weight status category (underweight, normal, overweight, obese class I–III). BMI is widely used as a screening measure in clinical risk assessment tools.
Radcalcs was built by a team of medical professionals and software engineers who use clinical calculators daily. Our clinical advisors include physicians across radiology, emergency medicine, cardiology, and nephrology who review calculator accuracy and ensure our content reflects current guidelines. We operate with the philosophy that medical decision support tools should be free, fast, and clinically reliable.
Our development process pairs clinical expertise with rigorous software implementation. Every formula is reviewed by a clinician in the relevant specialty before publication. When guidelines update, our clinical reviewers flag the change and the formula is revised against the new primary source.
All content on Radcalcs is reviewed against current peer-reviewed guidelines before publication. When guidelines update, we revise our tools and content within 90 days of the published update. We cite primary sources (original derivation studies and current guidelines) rather than secondary sources. If you identify an error, please contact us — we investigate all reports within 48 hours and issue corrections.
Our editorial standards:
All calculators are for informational and educational purposes only. Results must be interpreted by a qualified healthcare professional in the context of the full clinical picture. Not a substitute for clinical judgment or formal medical advice. Always verify calculations with current guidelines and your clinical team. See our full Medical Disclaimer for detail.
Questions, corrections, or feature requests? Email radbridge@polsia.app. We welcome clinician feedback on calculator accuracy. Error reports are prioritized and investigated within 48 hours.