K — Dialyzer Clearance
K represents the effective rate at which the dialyzer clears urea from the blood.
Hemodialysis Adequacy Tool
Kt/V Calculator
Estimate single-pool Kt/V and urea reduction ratio using values from one hemodialysis treatment session.
Instant result
Daugirdas II formula
Mobile friendly
Calculate Single-Pool Kt/V
Enter all values from the same dialysis session.
Calculator Guide
What Is a Kt/V Calculator?
A Kt/V calculator estimates how effectively urea is removed during hemodialysis. The result is commonly used as one part of dialysis adequacy assessment.
t — Treatment Time
t represents the total time for which the hemodialysis treatment was delivered.
V — Distribution Volume
V represents the estimated volume in which urea is distributed throughout the body.
Simple Process
How the Kt/V Calculator Works
The calculator uses the second-generation Daugirdas equation to estimate single-pool Kt/V.
Enter Pre-BUN
Add the BUN value measured before dialysis begins.
Enter Post-BUN
Add the BUN value measured after the dialysis session.
Add Session Details
Provide treatment time, fluid removed, and post-dialysis weight.
Review the Estimate
View the estimated spKt/V, URR, and general interpretation.
Result Guide
Understanding Your Kt/V Result
These ranges are general educational references for many patients receiving hemodialysis three times per week. Individual targets may differ.
| Estimated spKt/V | General interpretation |
|---|---|
| Below 1.2 | Below the commonly used minimum delivered dose for many thrice-weekly treatments. |
| 1.2 to 1.39 | At or above the common minimum but below the commonly used target of 1.4. |
| 1.4 or higher | At or above the common target for many patients treated three times weekly. |
A dialysis team may use different goals depending on treatment frequency, residual kidney function, clinical condition, sampling method, and other factors.
Common Questions
Kt/V Calculator FAQs
Find helpful answers about the calculation, inputs, units, and results.
Need clinical advice?
Discuss laboratory and dialysis results with the
treating care team.
Kt/V estimates the delivered dialysis dose in relation to the patient’s urea distribution volume. It mainly reflects urea removal during treatment.
For many patients receiving hemodialysis three times weekly, 1.4 is a commonly used target and 1.2 is a commonly used minimum delivered spKt/V. The treating team must determine the correct target.
Yes. Both BUN values may be entered in mg/dL or mmol/L because the equation uses their ratio. Use the same unit for both values.
URR is the percentage reduction in BUN. Kt/V also accounts for treatment time and ultrafiltration, providing a more detailed estimate of delivered dose.
No. This calculator is designed for single-session hemodialysis spKt/V. Peritoneal dialysis requires a different weekly Kt/V calculation.
Differences may result from sampling timing, treatment interruptions, access recirculation, laboratory methods, residual kidney function, or another kinetic modelling method.
Medical Disclaimer
This calculator provides an educational estimate only. It does not diagnose a condition, prescribe dialysis, or replace medical advice. Do not change treatment time, frequency, fluid removal, medication, or diet based on this result. Always consult the treating nephrologist or dialysis team.