Elysia Tools
Navigation
Health
Calculate the Urea Reduction Ratio (URR) for a single hemodialysis session: URR (%) = (Pre-BUN − Post-BUN) / Pre-BUN × 100. KDOQI recommends a minimum URR ≥65% and a target dose ≥70%. URR is a simple adequacy marker but is being phased out in favor of Kt/V, which also accounts for urea generation and volume contraction. Derived from the KDOQI Clinical Practice Guideline for Hemodialysis Adequacy. Valid for single hemodialysis sessions with BUN drawn pre- and immediately post-treatment; not for peritoneal dialysis. Not medical advice.
Execution
Fill in the form, run the tool, and review the result in one place.
Samples
Related
Tool usage guide
Calculate the Urea Reduction Ratio (URR) for one hemodialysis session using pre-dialysis and post-dialysis BUN values. The calculator applies URR = (Pre-BUN − Post-BUN) / Pre-BUN × 100% and compares the result with KDOQI reference thresholds of 65% minimum and 70% target. This tool is not medical advice.
Background
A single hemodialysis session has a pre-dialysis BUN of 90 mg/dL and a post-dialysis BUN of 27 mg/dL.
Problem
Calculate the percentage reduction and determine whether it meets the KDOQI target.
How to use
Enter 90 for Pre-dialysis BUN, 27 for Post-dialysis BUN, and use 4 decimal places.
{"preBun":90,"postBun":27,"decimalPlaces":4}Outcome
The calculator returns URR = 70.0000%, with the status Target met (≥70%).
Background
A hemodialysis session has a pre-dialysis BUN of 80 mg/dL and a post-dialysis BUN of 30 mg/dL.
Problem
Check whether the calculated URR meets the minimum KDOQI reference value.
How to use
Enter 80 for Pre-dialysis BUN, 30 for Post-dialysis BUN, and use 4 decimal places.
URR (%) = (Pre-BUN − Post-BUN) / Pre-BUN × 100.
The referenced KDOQI thresholds are a minimum of 65% and a target of 70% or higher.
It requires pre-dialysis BUN and post-dialysis BUN values in mg/dL. Decimal places are optional.
No. This calculator is intended for a single hemodialysis session.
No. URR is a simple marker and does not account for urea generation or volume contraction; Kt/V should be used to confirm full adequacy.
{"preBun":80,"postBun":30,"decimalPlaces":4}Outcome
The calculator returns URR = 62.5000%, with the status Below minimum (<65%).