Category
Nephrology & Fluids
Kidney function, electrolyte correction, and fluid balance tools.
Search this category
Tools in this category
Open any calculator — results are instant and private.
24h Fluid Balance
Net fluid balance over 24 hours.
In − out
BUN/Creatinine Ratio
Prerenal vs intrinsic kidney injury clue.
BUN/SCr
Corrected Sodium (Hyperglycemia)
Sodium correction for hyperglycemia.
Katz correction
Creatinine Clearance (24h urine)
Measured creatinine clearance from timed urine collection.
UV/P
Creatinine Clearance (CrCl)
Estimated creatinine clearance.
Cockcroft-Gault
Creatinine Height Index
Muscle mass screening in CKD.
CHI
Fractional Excretion of Sodium
Differentiates prerenal from ATN.
FENa
Fractional Excretion of Urea
Helps differentiate prerenal azotemia from acute tubular necrosis when diuretics were used.
FEUrea
Free Water Clearance
Free water handling estimate.
CH₂O
Kt/V (simplified)
Simplified dialysis adequacy estimate.
Dialysis adequacy
Maintenance Fluids (Holliday-Segar)
Pediatric/adult maintenance fluid estimate.
4-2-1 rule
Renal Resistive Index
Doppler renal resistive index for parenchymal disease assessment.
RRI = (PSV − EDV) / PSV