Kt/V & Standardized Kt/V Calculator

Assessing the adequacy of hemodialysis treatment

Last updated on: July 1, 2025

Dialysis Adequacy Calculator

mg/dL
mg/dL
kg
kg
hours
per week

What are Kt/V and Standardized Kt/V?

Kt/V is a number used to quantify hemodialysis treatment adequacy. "K" is the dialyzer clearance of urea, "t" is the dialysis time, and "V" is the patient's volume of distribution of urea. Single-pool Kt/V (spKt/V) measures the clearance from a single session.

Standardized Kt/V is an adjusted value that represents the overall weekly dialysis dose, allowing for comparison between different schedules (e.g., 3 times vs. 4 times a week). It is considered a more comprehensive measure of overall treatment adequacy.

Why is Dialysis Adequacy Crucial?

  • Ensures sufficient removal of waste products and toxins from the blood.
  • Directly linked to lower morbidity and mortality rates in dialysis patients.
  • Helps nephrologists tailor the dialysis prescription to individual patient needs.

Interpreting the Result (KDOQI Guidelines)

Inadequate Dialysis (spKt/V < 1.2): The delivered dialysis dose is below the minimum KDOQI target. The prescription should be re-evaluated.
Adequate Dialysis (spKt/V ≥ 1.2): The dialysis dose meets the minimum KDOQI target for thrice-weekly hemodialysis.

Factors Influencing Kt/V

Achieving the target Kt/V is a key goal of dialysis therapy. Several factors can be adjusted by the clinical team to improve the dose:

  • Increasing the duration of the dialysis session (t).
  • Using a larger or more efficient dialyzer (K).
  • Ensuring an adequate blood flow rate.
  • Verifying accurate pre and post-dialysis lab draws and weights.

This page has been medically reviewed by Dr. Khoulah Attia – PharmD, Immunology Specialist.