eGFR (MDRD)
Estimates GFR via simplified MDRD using serum creatinine, age, sex and ethnicity.
—
MDRD: estimating glomerular filtration rate
The MDRD equation (Modification of Diet in Renal Disease, 4-variable IDMS-traceable) estimates GFR normalized to 1.73 m²: eGFR = 175 · Scr^(−1.154) · age^(−0.203) · (0.742 if female) · (1.212 if Black) in mL/min/1.73 m². Take a man of 60 with Scr 1.0 mg/dL who is non-Black, and you get eGFR ≈ 175 · 1.0^(−1.154) · 60^(−0.203) ≈ 77 mL/min/1.73 m². Above 60 mL/min/1.73 m² it loses accuracy and reads low against the true GFR.
Clinical context
For years MDRD was the standard for CKD screening and staging under KDIGO criteria. CKD-EPI 2021 has since taken its place, since it's more accurate (especially for eGFR > 60) and carries no race coefficient. That race adjustment in MDRD drew criticism for having no biological basis and for feeding healthcare inequity. Reach for MDRD only when there's a historical reason, like legacy reports or a comparison against old measurements. When you're staging fresh, go with CKD-EPI 2021.
FAQ
MDRD or CKD-EPI? CKD-EPI 2021. MDRD is dated, and the race coefficient is no longer recommended.
Does it work for dose adjustment? No. For drug dosing you want Cockcroft-Gault, which gives absolute ClCr rather than a value normalized to 1.73 m².
Does it work in AKI? No. The formula assumes creatinine is at steady state, so it falls apart while renal function is still changing.
Related Tools
eGFR (CKD-EPI 2009)
Estimates GFR with the CKD-EPI 2009 equation — current standard for chronic kidney disease staging.
Email Open Rate Calculator
Enter emails sent, bounces and unique opens to get the rate on delivered mail: opens ÷ (sent − bounces) × 100. Above 30% rates as excellent.
Brazil Import Tax Calculator (Remessa Conforme)
Work out the import duty and ICMS a parcel pays on arrival in Brazil under the Remessa Conforme rules, before you check out on an overseas store.
Fund Management Fee Impact Calculator
Compounds an initial contribution at the gross annual return minus the management fee over the years you set and shows the final net balance in R$.
Falling-Rate Drying Period Time
Computes the duration of the falling-rate drying period under the model where the rate drops linearly with free moisture starting at the critical moisture: t = m_s × X_c ÷ (A × N_c) × ln(X_c ÷ X₂). Moisture contents go in as free moisture on a dry basis, that is, with the equilibrium moisture already subtracted, which is why X₂ can never be zero — drying down to equilibrium would take infinite time, exactly what the logarithm says. Compared with the constant-rate period this is the expensive stretch: every kilogram of water removed costs far more time than in the previous stretch, because internal transport now sets the pace. Enter the dry solid mass, the critical moisture, the final free moisture, the exposed area and the constant rate at the critical moisture.
Interest Rate Calculator
Calculate simple and compound interest. Enter the principal, rate and period to get the interest and final amount.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.