EBM Consult

Adult Glomerular Filtration Rate (GFR) Calculator

Change all to SI units?:

Gender:   
Race:   
Age: years    (if < 18 yrs use Peds Calculator)
Height:
  or
Weight:
 
Cr:
BUN:
Albumin:

Does your lab use creatinine methods recalibrated to be traceable to IDMS? What is this?

Results

eGFR per CKD-EPI:
eGFR per MDRD4:
eGFR per MDRD6:
eGFR per MDRD4 x BSA:
eGFR per MDRD6 x BSA:

Other Results

Body Mass Index (BMI):
Total Body Wt (TBW):
Ideal Body Wt (IBW):
Lean Body Wt (LBW):
Adjusted Body Wt (ABW):
Percent Under/Over (IBW):
Body Surface Area (BSA):
using Boyd formula
using DuBois formula
using Gehan & George formula
using Haycock formula
using Mosteller formula





Assumptions for the use of this Adult Estimated GFR Calculator:
1. 
The patient is > 18 years of age. If you are looking for the Pediatric eGFR Calculator click here 
2.
The renal function is considered stable (i.e., not in acute renal failure) and the patient does not have significant liver disease 
3.
You should know if your institution's lab or outside lab has changed to measuring creatinine assays that are IDMS traceable or not. If you are not sure or cannot find out, then leave box unchecked. If you want to know more about this please click here 


Formulas Used:
eGFR per CKD-EPI = 141 x min(Cr/k, 1)a x max(Cr/k, 1)-1.209 x 0.993age x 1.018[if female] x 1.159[if black/African American]
k = 0.7 for females; 0.9 for males
a = -0.329 for females; -0.411 for males, min indicates the minimum of Cr/k or 1, and max indicates the maximum of Cr/k or 1

eGFR per MDRD4 = 186 x creatinine-1.153 x age-0.203 x (0.742 if female) x (1.212 if black/African American)
eGFr per MDRD6 = 170 × (serum Cr)-0.999 × age-0.176 × (BUN)-0.17 × albumin0.318 × 0.762[if female] × 1.18[if African American]

CONSIDERATIONS:

The Normal or Maximum estimated GFR (eGFR):
The estimated glomerular filtration rate (eGFR) is not accurate above 60 ml/min/1.73m2. Per the National Kidney Foundation (NKF), for values greater than this the result should be reported as being: ≥ 60 ml/min/1.73m2.

Staging for Chronic Kidney Disease (CKD):
It is also important to note that currently the staging of chronic kidney disease (CKD) is based on the estimated GFR not the CrCl. To calculate the CrCl click here. To calculate all estimated values for assessing renal function, visit the Comprehensive Renal Function Calculator.

Staging should be done in patients who meet the following criteria for CKD: 
1. 
Kidney damage for ≥3 months, as defined by structural or functional abnormalities of the kidney, with or without decreased GFR, manifest by either: pathological abnormalities; or markers of kidney damage, including abnormalities in the composition of the blood or urine or abnormalities in imaging tests.
2.
GFR <60 ml/min/1.73m2 for ≥3 months, with or without kidney damage.
3.
If the above criteria is meet, then the patient can be staged: 
  Stage 1 or 2: GFR = >60 ml/min/1.73m2 
  Stage 3:        GFR = 30-59 ml/min/1.73m2 
  Stage 4:        GFR = 15-29 ml/min/1.73m2 
  Stage 5:        GFR = <15 ml/min/1.73m2 


MDRD 4 vs. MDRD 6 Variable Results:

The MDRD 4 variable is the most common eGFR formula used in clinical practice. However, given the broad range of clinicians that use these calculators for various reasons, the additional results for the MDRD 6 variable are provided since it is also another common equation also evaluated in the original MDRD study. Furthermore, the corrected MDRD 4 and MDRD 6 variable results are done to adjust for the body surface area (BSA) should the clinician be interested in that information.

For information and supporting references regarding the BMI, BSA, and weights please click here

References:

1. 
National Kidney Foundation. K/DOQI Clinical Practice Guidelines for Chronic Kidney Disease: Evaluation, Classification and Stratification. Am J Kidney Dis 2002;39(suppl 1):S1-S266. PubMed   NKF 
2.
Levey AS, Bosch JP, Lewis JB, et al. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of diet in renal disease study group. Ann Intern Med 1999;130:461-70. PubMed 
3. 
Levey AS, Coresh J, Greene T et al. Expressing the Modification of Diet in Renal Disease Study equation for estimating glomerular filtration rate with standardized serum creatinine values. Clin Chem 2007;53:766-72. PubMed 
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;18:2749-57. PubMed 


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