BUN to Creatinine Ratio Calculator
Enter BUN and creatinine from your blood test.
Your numbers
Your results
BUN to Creatinine Ratio Calculator by TheCalcTools
How the BUN to Creatinine Ratio Calculator works
The ratio compares two waste products cleared by the kidneys. In US units it is BUN (mg/dL) ÷ creatinine (mg/dL). In SI units, urea (mmol/L) × 2.8 gives BUN in mg/dL and creatinine (µmol/L) ÷ 88.4 gives mg/dL.
A ratio around 10 to 20 is common. Interpretation depends on the whole clinical picture.
The formula
Worked example
Using the default values shown in the calculator:
| Units | BUN mg/dL, creatinine mg/dL |
|---|---|
| BUN or urea | 18 |
| Creatinine | 1 |
- BUN 18 and creatinine 1.0: ratio 18.0, Normal range (10 to 20).
Result:
| BUN/creatinine ratio | 18.0 |
|---|---|
| Typical interpretation | Normal range (10 to 20) |
Frequently asked questions
Is a high ratio always dehydration?
No. Gastrointestinal bleeding, steroids, high protein intake and heart failure can also raise it.
Sources and further reading
Related calculators
More in Health & Fitness · All calculators
This calculator gives general estimates for information and education. It is not medical advice and does not diagnose anything. Talk to a qualified health professional about your own situation. See our disclaimer.