Methodology and references
Review status
Clinical review
⚠ This content has not yet been independently reviewed by a licensed clinician.
Every equation on this site is implemented directly from its original peer-reviewed publication and covered by an automated test suite that checks the arithmetic against published reference values. That verifies the maths. It does not substitute for a clinician reviewing the clinical guidance, thresholds and caveats that surround it.
We would rather say this plainly than display a review badge we have not earned. Until a named licensed reviewer has signed off, treat this site as a calculation aid to be checked against your own references — not as a clinically reviewed source.
If you are a licensed pharmacist, physician or nurse practitioner and would be willing to review this content, please get in touch.
Equations
Every formula, with its source
| Equation | Used on | Primary source |
|---|---|---|
| Cockcroft-Gault | All CrCl pages | Cockcroft DW, Gault MH. Nephron. 1976;16(1):31–41. |
| Devine ideal body weight | CrCl pages | Devine BJ. Drug Intell Clin Pharm. 1974;8:650–5. |
| Adjusted body weight (0.4 factor) | CrCl pages | Bauer LA, et al. Clin Pharmacol Ther. 1983;33(4):519–25. |
| Salazar-Corcoran | Special populations | Salazar DE, Corcoran GB. Am J Med. 1988;84(6):1053–60. |
| Limb-mass proportions | Special populations | Osterkamp LK. J Am Diet Assoc. 1995;95(2):215–18. |
| CKD-EPI 2021 creatinine (race-free) | eGFR page | Inker LA, et al. N Engl J Med. 2021;385:1737–49. |
| CKD-EPI 2021 creatinine + cystatin C | eGFR page | Inker LA, et al. N Engl J Med. 2021;385:1737–49. |
| CKD-EPI 2012 cystatin C | eGFR page | Inker LA, et al. N Engl J Med. 2012;367:20–9. |
| Bedside Schwartz (paediatric) | eGFR, special populations | Schwartz GJ, et al. J Am Soc Nephrol. 2009;20(3):629–37. |
| MDRD (legacy, comparison only) | eGFR page | Levey AS, et al. Ann Intern Med. 2006;145(4):247–54. |
| Du Bois body surface area | All pages | Du Bois D, Du Bois EF. Arch Intern Med. 1916;17:863–71. |
| KDIGO GFR categories | eGFR page | KDIGO 2012 CKD Guideline. Kidney Int Suppl. 2013;3:1–150. |
Editorial policy
How this content is written
What we commit to
- Every equation is implemented from its original publication, and every constant is cited.
- Every calculation is covered by automated tests asserting against published reference values.
- Limitations are stated alongside results, not buried in a footnote.
- Where guidance is convention rather than evidence, we say so explicitly.
- Where an equation should not be used — Cockcroft-Gault in children, for instance — the tool refuses to offer it rather than trusting the user to know.
- Corrections take priority over new features.
Privacy, by architecture rather than by promise
All calculations run entirely in your browser. No patient values are transmitted, logged or stored.
This is not a policy decision that could quietly change — it is how the site is built. The calculation code is a set of pure functions that run in your browser. There is no API endpoint that accepts a patient value, because there is no API endpoint at all. There is no database.
Values are not written to local storage either, so closing the tab discards them. Unit preferences are the only thing the interface remembers, and only for the current session.
Independence
Affiliation and funding
CrCl Calculator is independent. It is not affiliated with, endorsed by, or connected to MDCalc, GlobalRPH, any university, hospital system, professional body, or pharmaceutical company. Where those organisations are named on this site, it is as a neutral factual reference only.
There is no advertising on the calculator pages, no sponsored content, and no commercial relationship influencing which equations are presented or how they are described.
Disclaimer
Scope and limits
This calculator is intended for healthcare professional reference and educational purposes only. It does not replace clinical judgment or the advice of a licensed provider. Always verify dosing decisions against institutional protocol and current prescribing information.
All estimating equations on this site assume stable renal function. None of them is valid in acute kidney injury, where serum creatinine lags behind the true filtration rate. No calculator can substitute for clinical assessment of the patient in front of you.
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Calculators on this site
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Standard adult creatinine clearance with actual, ideal and adjusted body weight side by side.
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CKD-EPI 2021 creatinine, cystatin C and combined equations, plus Schwartz for children and a CrCl comparison.
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Weight-basis selection, Salazar-Corcoran, amputation correction, paediatric equations and mL/hour output.
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Measured clearance from a timed collection, with a collection-adequacy check and BSA normalisation.
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Found something wrong?
Clinical corrections are treated as a priority. If an equation, a threshold or a caveat on this site is inaccurate, we want to know.
Medical disclaimer: This calculator is intended for healthcare professional reference and educational purposes only. It does not replace clinical judgment or the advice of a licensed provider. Always verify dosing decisions against institutional protocol and current prescribing information.