Bone & Mineral Metabolism
Every bone & mineral metabolism calculator on CalcEngines — unit converters, derived indices and interpretive tools, each with its formula, a worked example and the reference intervals it is judged against.
21 calculators in this section
- Beta-CrossLaps (CTX) Unit ConverterConvert serum beta-CrossLaps between ng/L, pg/mL, µg/L and ng/mL — and read the result knowing that CTX must be sampled fasting and before 10 a.m., because a fed afternoon sample can be half the fasting morning value.
- BMD T-Score and Z-Score CalculatorCompute a T-score or a Z-score from a measured bone mineral density and its reference values — and get the right one, because a T-score in a premenopausal woman or a man under 50 is a diagnosis the ISCD says cannot be made that way.
- Bone Turnover Marker InterpreterRead P1NP and CTX as a change from baseline on osteoporosis treatment — with the least significant change, the drug class that decides which direction to expect, and the fasting morning sample that makes a CTX interpretable at all.
- Calcitriol (1,25-Dihydroxyvitamin D) ConverterConvert 1,25-dihydroxyvitamin D between pg/mL, ng/L and pmol/L — and read the result knowing that calcitriol is a different analyte from 25-hydroxyvitamin D and is not the test for vitamin D status.
- Calcium Unit ConverterConvert total calcium between mg/dL, mmol/L, mEq/L and mg/L — and get the divalent step right, because mEq/L is twice the mmol/L figure, not the same as it.
- Calcium-Creatinine Clearance Ratio CalculatorSeparate familial hypocalciuric hypercalcaemia from primary hyperparathyroidism using the 24-hour calcium-creatinine clearance ratio.
- Corrected Calcium CalculatorAdjust total serum calcium for a low albumin using the traditional correction formula, and see why it should not be trusted alone in sick patients.
- Elemental Calcium Content ConverterConvert a calcium salt dose to its elemental calcium content — the figure that dosing guidelines and prescriptions actually specify.
- Hypercalcaemia Cause Interpreter: PTH, FHH, PTHrP & Vitamin DFind the cause of a high calcium. Read the PTH taken with it against your own reference interval — suppressed, inappropriately normal or raised — to split PTH-dependent from PTH-independent hypercalcaemia. Then ask the familial hypocalciuric hypercalcaemia (FHH) question with the calcium:creatinine clearance ratio, or work through PTHrP, 1,25-dihydroxyvitamin D, 25-hydroxyvitamin D and a myeloma screen.
- Hypercalcaemia Severity ClassifierGrade a hypercalcaemia on albumin-corrected calcium in mmol/L and mg/dL, with both published band sets attributed — because they disagree between 3.4 and 3.5 — and with the clinical state and the PTH branch built in.
- Hypocalcaemia Severity InterpreterGrade a hypocalcaemia on albumin-corrected calcium in mmol/L and mg/dL, with both published severity sets attributed, the clinical state outranking the number, and the two results that change management built in — the PTH branch and the magnesium.
- Osteocalcin Unit ConverterConvert serum osteocalcin between ng/mL, µg/L and nmol/L — with the caution that osteocalcin assays measure different mixtures of intact protein and fragments, so results are not comparable between methods.
- P1NP Unit ConverterConvert procollagen type I N-terminal propeptide between µg/L, ng/mL and ng/L — the reference marker of bone formation, read as a change from baseline on one assay rather than as a single number.
- Parathyroid Hormone (PTH) Unit ConverterConvert intact PTH between pg/mL, pmol/L and ng/L, and see why a PTH from one laboratory cannot be compared with a PTH from another.
- Phosphate Unit ConverterConvert serum phosphate between mg/dL, mmol/L and mg/L — and see why the factor uses the atomic weight of phosphorus rather than that of phosphate.
- Potassium Salt (mEq, mmol, mg) ConverterConvert a potassium salt dose in milligrams to mmol (equal to mEq for this monovalent ion), across the common oral salts.
- Primary Hyperparathyroidism Surgery Criteria (2022 Workshop)Check whether asymptomatic primary hyperparathyroidism meets the criteria for parathyroidectomy from the Fifth International Workshop (2022): calcium more than 0.25 mmol/L (1 mg/dL) above the upper limit, a T-score of −2.5 or less, a vertebral fracture, eGFR or creatinine clearance below 60, kidney stones or nephrocalcinosis, high 24-hour urine calcium, or age under 50. Any one is enough. The page also shows what changed from the 2014 Fourth Workshop.
- TmP/GFR Calculator (Renal Phosphate Threshold)Calculate the renal tubular maximum phosphate reabsorption threshold (TmP/GFR) using the Walton-Bijvoet formula, the most sensitive test for renal phosphate wasting.
- Vitamin D IU to mcg ConverterConvert vitamin D doses between international units and micrograms, and see how dosing relates to the measured 25-hydroxyvitamin D level.
- Vitamin D Loading Dose CalculatorWork out a vitamin D loading schedule from a published regimen — the UK's 300,000 IU total over six to ten weeks, or the Endocrine Society's 50,000 IU weekly for eight — and see the dose per administration, the total and the daily equivalent side by side.
- Vitamin D Status InterpreterPlace a 25-hydroxyvitamin D against every framework still in circulation — Endocrine Society 2011, withdrawn by the Endocrine Society in 2024, and the IOM's genuinely different position — in ng/mL and nmol/L, without pretending one has won.