This tool is designed by Dr Michał Bartoszek to facilitate a choice of everyday calculations suitable for assesment of the results of hemodialysis.

The Kt/V calculator may be used to determine the adequacy of dialysis treatment. It uses the Daugirdas II equation for Single Pool (spKt/V) (Daugirdas, 1993)1, the Tattersall equation for Equilibrated Single Pool (eKt/V) (Tattersall et al., 1996)2 and the Leypoldt equation for Standard (stdKt/V) (Leypoldt et al., 2004)3 calculations.

 Current guidelines for hemodialysis adequacy are based on Kt/V, the fractional removal of urea per dialysis treatment,4 expressed as clearance (K) multiplied by treatment time (t) and divided by the urea distribution volume (V).

For three treatments per week, the 2006 Kidney Disease Outcomes Quality Initiative (KDOQI) adequacy guidelines5 recommend a minimum single-pool Kt/V of 1.2. The European Best Practice Guidelines recommend a minimum equilibrated Kt/V value of 1.2 corresponding to a minimum single-pool Kt/V of 1.35–1.40.When evaluating adequacy of hemodialysis schedules other than three times per week, the treatment Kt/V is an insufficient measure of outcome, as it does not reflect the greater or lesser amount of dialysis being delivered due to more or fewer treatments per week. For such schedules, use of the so-called ‘standard Kt/V’ (stdKt/V)3 to ensure minimum adequacy has been recommended . It can be estimated from equilibrated treatment Kt/V, session length and number of treatment per week by an equation proposed by Leypoldt.3 For other than 3/week dialysis schedules, KDOQI proposed a minimum value of 2.0 for stdKt/V (Daugirdas et al.,2012).


  1. 1. Daugirdas JT, Second generation logarithmic estimates of single-pool variable volume Kt/V, J Am Soc Nephrol. 1993 Nov;4(5):1205-13

  1. 2. Tattersall JE, DeTakats D, Chamney P, Greenwood RN, Farrington K (December 1996). "The post-hemodialysis rebound: predicting and quantifying its effect on Kt/V". Kidney Int.50 (6): 2094–102

3. Leypoldt JK, Jaber BL, Zimmerman DL (2004). "Predicting treatment dose for novel therapies using urea standard Kt/V". Seminars in Dialysis 17 (2): 142–5

4. URR - Lowrie EG, Lew NL. The urea reduction ratio (URR). A simple method for evaluating hemodialysis treatment. Contemp Dial Nephrol 1992;12:11

5. "CLINICAL PRACTICE GUIDELINES FOR HEMODIALYSIS ADEQUACY,2006" - NKF KDOQI (The National Kidney Foundation Kidney Disease Outcomes Quality Initiative).


Kt/V Calculator

Kt / V   Calculator

v 1.0

© 2013 Developed by:  Slawomir Janiec, MD