Calcium Creatinine Clearance Ratio Calculator

Calcium Creatinine Clearance Ratio Calculator for Endocrinology. Below 0.01, 0.01-0.02 inclusive and above 0.02 are descriptive numerical bands, not diagnoses. A low ratio can occur in PHPT, and a higher result cannot independently exclude FHH. The output is a clearance ratio, not absolute urinary calcium excretion.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

CCCR = urine calcium x serum creatinine / (serum calcium x urine creatinine), after matching concentration units within each analyte. SI serum creatinine is entered in micromol/L and divided by 1000 to match urine creatinine in mmol/L. US calcium uses 0.2495 and creatinine 88.4 micromol/L per mg/dL.

When to use this calculator

Use concurrent blood and appropriate 24-hour urine measurements as part of the differential assessment of hypercalcemia. The PARAT consensus emphasizes overlap between familial hypocalciuric hypercalcemia (FHH) and primary hyperparathyroidism (PHPT). Review sampling, medications and biochemical context before interpreting the ratio.

Inputs used

  • Urine and serum calcium in mmol/L or mg/dL
  • Urine creatinine in mmol/L or mg/dL
  • Serum creatinine in micromol/L or mg/dL

Clinical interpretation

Below 0.01, 0.01-0.02 inclusive and above 0.02 are descriptive numerical bands, not diagnoses. A low ratio can occur in PHPT, and a higher result cannot independently exclude FHH. The output is a clearance ratio, not absolute urinary calcium excretion.

Worked example

Urine calcium 1.8, serum calcium 2.7 and urine creatinine 6 mmol/L, with serum creatinine 70 micromol/L, give 1.8 x 0.070 / (2.7 x 6) = 0.007778. Enter 70, not 0.070, in the serum SI field. Exactly 0.01 and 0.02 both remain in the inclusive intermediate numerical band.

Limitations and safety notes

Renal impairment, vitamin D status, calcium intake, medications and pregnancy can limit interpretation. Family history and genetic evaluation may be important. Zero denominators are rejected rather than displayed as zero. This result must not independently determine parathyroid surgery or medication changes.

Frequently asked questions

Is serum creatinine 0.070 the correct SI entry?

No. That is mmol/L; this serum field expects micromol/L, so the equivalent entry is 70. Urine creatinine retains mmol/L.

Does a result below 0.01 prove FHH?

No. The conditions overlap, and confounders can lower the ratio. Interpret it within a broader clinical and family assessment.

References

  • PARAT 2021 expert consensus published 2022; concurrent blood and 24-hour urine, CCCR overlap between FHH and PHPT and limitations in renal impairment, vitamin D insufficiency and pregnancy. https://pmc.ncbi.nlm.nih.gov/articles/PMC8789028/

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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