Urr
Urr is a fast, free health calculator. Enter Pre-dialysis BUN and Post-dialysis BUN to get an instant, accurate result — complete with the formula, a step-by-step worked example, and answers to common questions, all on one page and private to your browser.
Formula
URR = (1 − post-BUN/pre-BUN) × 100%
- URR = (1 − post-BUN/pre-BUN) × 100% — for clinical reference only.
Urr
Urr calculation.
Frequently asked questions
Is this validated?
Yes, based on published clinical scoring systems. Always confirm with current guidelines.