eGFR Calculator
Estimated GFR with the race-free CKD-EPI 2021 equations and CKD stage.
Enter your values to see the result.
Uses the race-free CKD-EPI 2021 equations recommended by the NKF-ASN task force, with MDRD shown for comparison. Only valid for adults with stable kidney function, not in acute kidney injury, pregnancy or extremes of muscle mass. For education and clinical decision support only. Results do not replace professional judgment, local protocols or the product information, so always verify doses and values before acting on them.
Processing and privacy
Processing varies by tool. Check the instructions for local processing, server requests, external services and any file or request limits before entering sensitive information.
Read the privacy policyHow this calculation works
Understand the method, inputs and limits behind your result.
- Formula
- CKD-EPI 2021 creatinine: eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 (if female). κ = 0.7 for women or 0.9 for men; α = −0.241 for women or −0.302 for men. With cystatin C entered, the combined equation is used; MDRD is shown for comparison.
- Variables
- Scr = serum creatinine in mg/dL; this implementation divides µmol/L by 88.42
- Age = age in years
- κ and α = sex-specific coefficients
- Cystatin C = optional concentration in mg/L
- Units
- eGFR: mL/min/1.73 m²
- Creatinine: mg/dL or µmol/L
- Cystatin C: mg/L
- Example
- A 55-year-old man with a creatinine of 1.1 mg/dL (97 µmol/L) has an eGFR of 79 mL/min/1.73 m², stage G2.
- Assumptions
- Adult estimate with stable kidney function and standardized laboratory measurements. Acute kidney injury, pregnancy and extremes of muscle mass can make it unreliable. A single result does not establish chronic kidney disease.
- Last reviewed
- Implementation review; specialist review has not been recorded.
Methodology & References
The method depends on the selected model and input options. Review the assumptions and references above before interpreting the result.
- Enter sex, age and serum creatinine in mg/dL or µmol/L.
- Add cystatin C if you have it for a more accurate estimate.
- Read the eGFR in mL/min/1.73 m² and the CKD stage.
Interpretation and limitations
- Why is there no race coefficient? The 2021 CKD-EPI equations were refitted without race, as recommended by the NKF-ASN task force, and are now the US standard.
- When is eGFR unreliable? In acute kidney injury, pregnancy, very high or low muscle mass, amputations and extreme diets. Measured clearance or cystatin C helps then.
- Can I use this to make treatment decisions? It supports education and clinical decision-making but does not replace clinical judgment, local protocols or product information. Always double-check results.
References
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Clear instructions
Find steps, examples and limitations below.
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How to use the eGFR Calculator
Estimated GFR with the race-free CKD-EPI 2021 equations and CKD stage.
- 1 Enter sex, age and serum creatinine in mg/dL or µmol/L.
- 2 Add cystatin C if you have it for a more accurate estimate.
- 3 Read the eGFR in mL/min/1.73 m² and the CKD stage.
Example and practical tips
A 55-year-old man with a creatinine of 1.1 mg/dL (97 µmol/L) has an eGFR of 79 mL/min/1.73 m², stage G2.
Further reading
Frequently asked questions
Why is there no race coefficient?
The 2021 CKD-EPI equations were refitted without race, as recommended by the NKF-ASN task force, and are now the US standard.
When is eGFR unreliable?
In acute kidney injury, pregnancy, very high or low muscle mass, amputations and extreme diets. Measured clearance or cystatin C helps then.
Can I use this to make treatment decisions?
It supports education and clinical decision-making but does not replace clinical judgment, local protocols or product information. Always double-check results.
Practical guides
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How to Use eGFR Calculator
Estimate GFR with the race-free CKD-EPI 2021 creatinine and creatinine–cystatin C equations, compare with MDRD and see the CKD stage from G1 to G5.
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