MDRD eGFR Calculator

Methodology

MDRD study equation (IDMS-traceable, 2006)

175 × Scr^−1.154 × age^−0.203 × 0.742 [female]

Superseded by CKD-EPI. The race coefficient (×1.212) is deliberately not applied, in line with current practice.

Who it is for

Adults; most accurate below 60 mL/min/1.73 m².

Version

1.0.1

How this calculator works

Where the formula comes from

• Levey and colleagues (1999) derived the MDRD Study equation from serum creatinine and patient characteristics in people with chronic kidney disease, using measured GFR as the reference.^[1]
• In 2006 the 4-variable equation was re-expressed for creatinine traceable to isotope-dilution mass spectrometry; in 1,628 MDRD Study patients 90% of estimates were within 30% of measured GFR.^[2]

The inputs

• The IDMS-traceable 4-variable equation is 175 × creatinine (mg/dL)^−1.154 × age^−0.203, × 0.742 for women and historically × 1.212 for Black patients; this calculator omits the race factor, which is not the same as using the race-free CKD-EPI 2021 equation.^[2]

Versions and alternatives

• The CKD-EPI equation (2009) was more accurate than the MDRD equation, especially at higher GFR, and was proposed to replace it for routine use.^[3]

Where accuracy falls (published evidence)

• The MDRD Study included few patients with GFR above 90, and the equation was less accurate (larger differences from measured GFR) when estimated GFR was 60 or more.^[2]
• In 5,504 people from 10 studies the equation gave unbiased and reasonably accurate estimates when estimated GFR was below 60 mL/min/1.73 m²; estimates near 60 should be interpreted with caution.^[4]

What guidelines say

• KDIGO 2024 recommends a validated estimating equation rather than serum creatinine alone, and states that race should be avoided in eGFR calculation.^[5]

Sources

1. Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Ann Intern Med. 1999;130(6):461–470. doi:10.7326/0003-4819-130-6-199903160-00002
2. Levey AS, Coresh J, Greene T, et al. Using standardized serum creatinine values in the Modification of Diet in Renal Disease study equation for estimating glomerular filtration rate. Ann Intern Med. 2006;145(4):247–254. doi:10.7326/0003-4819-145-4-200608150-00004
3. Levey AS, Stevens LA, Schmid CH, et al. A new equation to estimate glomerular filtration rate. Ann Intern Med. 2009;150(9):604–612. doi:10.7326/0003-4819-150-9-200905050-00006
4. Stevens LA, Coresh J, Feldman HI, et al. Evaluation of the Modification of Diet in Renal Disease study equation in a large diverse population. J Am Soc Nephrol. 2007;18(10):2749–2757. doi:10.1681/ASN.2007020199
5. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2024;105(4S):S117–S314. doi:10.1016/j.kint.2023.10.018

Compiled from the published sources above. Every statement was agreed independently by three AI research tools (Claude, ChatGPT, DeepSeek) and its source verified in PubMed or Crossref by the Hakeemly editorial team. Not reviewed by a doctor unless stated. Agreed on 2026-10-12

Worked example: how to calculate MDRD eGFR

Calculation:

175 × 50^−0.203 = 175 × 0.4518 = 79.07

An illustration with sample values, worked out with the same method the tool above uses.

Limitations

• Less accurate at GFR of 60 and above; the CKD-EPI equation (2009) performed better, especially at higher GFR. KDIGO 2024 advises a validated equation without race, used consistently within a region.
• Less accurate with unusual muscle mass (bodybuilders, amputations, frailty), vegetarian diets, pregnancy and acute kidney injury.

References

1. Levey AS, Coresh J, Greene T, et al. Using standardized serum creatinine values in the Modification of Diet in Renal Disease study equation for estimating glomerular filtration rate. Ann Intern Med. 2006;145(4):247–254. doi:10.7326/0003-4819-145-4-200608150-00004
2. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2024;105(4S):S117–S314. doi:10.1016/j.kint.2023.10.018