Urine calcium to creatinine ratio calculator
Calcium in one urine sample compared with creatinine, which adjusts for how dilute the urine is. It is used for stone and bone work-ups in adults and children. Type your results in the units on your report and it works out Urine Ca/Cr ratio as you type, in your browser.
AI-verified against cited sources. Awaiting expert reviewLast reviewed 2026-10-03Urine Tests
Type your results above, or fill in the example, to see Urine Ca/Cr ratio.
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Educational information, not medical advice. Blood Test Tracker doesn’t diagnose or treat, and it doesn’t replace your clinician. Talk with your clinician before changing medications, supplements or care.
How it’s worked out
The formula
Urine Ca/Cr (mg/mg) = urine calcium (mg/dL) ÷ urine creatinine (mg/dL). Multiply by 1,000 for mg/g.
A worked example
Example numbers, not anyone’s real results, run through the same code as the calculator above.
| Urine calcium | 10 mg/dL |
|---|---|
| Urine Creatinine | 100 mg/dL |
| Urine Ca/Cr ratio | 0.10 mg/mg |
For an adult, this result is in the usual range.
What Urine Ca/Cr ratio tells you
This test measures calcium and creatinine in the same urine sample and divides one by the other. Creatinine is a waste product your muscles release at a fairly steady rate, so the ratio adjusts for how watery or concentrated the urine is. That lets a lab estimate how much calcium you are losing without a 24-hour collection. Normal values are higher in babies and fall through childhood to adult levels.
Mayo Clinic Laboratories lists this ratio for judging kidney stone risk and for looking into bone diseases such as osteoporosis and osteomalacia. It is also a practical option in children, when a 24-hour collection is hard to get. In adults who form stones, a 24-hour collection is still the main test, so a ratio is often a first look. The ratio comes from one sample, so it can swing with meals and fluids. Unexpected results are often repeated or followed by a 24-hour collection.
Read the full page on Urine Ca/Cr ratio, with what a high or low result can mean.
Usual ranges
The ranges the result above is placed on. Your own lab’s printed range comes first if it gives one.
- 0.08–00.03–0.81 mg/mg
Source: Mayo Clinic Laboratories
- 10.03–0.56 mg/mg
Source: Mayo Clinic Laboratories
- 20.02–0.5 mg/mg
Source: Mayo Clinic Laboratories
- 3–40.02–0.41 mg/mg
Source: Mayo Clinic Laboratories
- 5–60.01–0.3 mg/mg
Source: Mayo Clinic Laboratories
- 7–90.01–0.25 mg/mg
Source: Mayo Clinic Laboratories
- 10–170.01–0.24 mg/mg
Source: Mayo Clinic Laboratories
- 18–830.05–0.27 mg/mg
Source: Mayo Clinic Laboratories
Sources
The equation
- Calcium/Creatinine Ratio, Random, Urine (Mayo test CACR3), Mayo Clinic Laboratories
6 more sources for the ranges and the explanation
- Calcium, Urine (ARUP test 0020472), ARUP Laboratories
- Calcium in Urine Test (MedlinePlus Medical Test), MedlinePlus, U.S. National Library of Medicine
- Calcium - urine (MedlinePlus Medical Encyclopedia), MedlinePlus, U.S. National Library of Medicine (2025)
- Nutritional Management of Kidney Stones (Nephrolithiasis), Clinical Nutrition Research (2015)
- Kidney Stone Pathophysiology, Evaluation and Management: Core Curriculum 2023, American Journal of Kidney Diseases (2023)
- European expert consensus on practical management of specific aspects of parathyroid disorders in adults and in pregnancy: recommendations of the ESE Educational Program of Parathyroid Disorders (PARAT 2021), European Journal of Endocrinology (European Society of Endocrinology) (2022)
AI-verified against cited sources. Awaiting expert review. Last reviewed 2026-10-03. The calculator is version 1.0.0 of our code for this equation, tested against published examples. How we build and check these pages.