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Potassium-to-Creatinine Ratio

Published: August 9, 2026Updated: August 16, 2026

This calculated test compares potassium with creatinine to help evaluate potassium balance and kidney function. Interpretation depends on the specimen used.

Quick summary

["The result is interpreted alongside potassium and creatinine levels, the specimen type, and your clinical situation."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
11148-4
Short code
Potassium/Creat Ur
Synonyms
Potassium/Creat Ur
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Ref low
3.5
Ref high
5
Critical range
2.5 N/A – 6.5 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
84132
SNOMED
110742001
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

The potassium-to-creatinine ratio compares the amount of potassium with the amount of creatinine in the same sample. Creatinine is a waste product filtered by the kidneys, so the ratio can provide context when potassium or kidney function results are evaluated.

Why might I need this test?

Clinicians may use this test to help assess potassium levels, kidney function, hydration, or changes in potassium intake. A urine ratio may help evaluate potassium loss, while interpretation of other specimen types can differ.

How is the test performed?

Potassium and creatinine are measured separately from a laboratory specimen, usually blood or urine. The laboratory then calculates the ratio; the result is not usually obtained from a single direct test.

How do I prepare for the test?

Follow the laboratory's instructions for the specific specimen. Some urine tests require a timed collection, and you may be asked to record fluid intake. Do not stop medicines or change your diet unless your clinician advises you to do so.

Reference range

Adult: 3.5-5.0 mmol/LN/A

Specimen: urine

No special preparation required. Stay well hydrated.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Potassium/Creatinine Ratio

Frequently asked questions

Is a potassium-to-creatinine ratio the same as a potassium blood test?
No. The potassium blood test measures potassium directly, while the ratio compares potassium with creatinine. A separate potassium result is generally available when the ratio is reported.
Why does the specimen type matter?
A urine ratio mainly helps evaluate how much potassium the body is losing, while a blood or plasma ratio is interpreted differently. Always confirm which specimen was used.
What can affect the result?
Kidney function, hydration, recent potassium intake, medicines, and the timing or completeness of urine collection can affect the result. A clinician can interpret the ratio in that context.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy