Converter

Choose a conversion type first, then select the specific analyte or unit. This original Perinatology tool separates general units, common obstetric labs, chemistry, endocrine, hematology/coagulation, vitamins/nutrition, enzymes, and additional specialized laboratory conversions.

Conversion type filters >
Select a group to narrow the calculator list.
Type part of a lab or unit name, then choose from the filtered list below.
Tip: Press Enter in the input field to convert.
Additional quick conversions
Clinical note: Unit conversion does not verify the clinical meaning of a value. Confirm the specimen type, assay, reference interval, and local laboratory reporting convention before using converted values in clinical care.
Included conversion groups

This consolidated tool is now separated into practical conversion sections, similar to a conversion-directory workflow but with original Perinatology styling and clinical/laboratory organization.

Sectioned clinical and laboratory conversions
  • General units: mass/weight, length, volume, temperature, pressure.
  • Chemistry and minerals: albumin/total protein, bilirubin, BUN/urea, calcium, cholesterol, copper, creatinine, glucose, ionized calcium, magnesium, phosphate, triglycerides, uric acid.
  • Endocrine and pregnancy: 17-hydroxyprogesterone, aldosterone, beta-hCG, DHEA-S, estradiol, prolactin, progesterone, thyroid tests.
  • Hematology/coagulation: D-dimer, fibrinogen, hemoglobin, platelets, WBC.
  • Vitamins/nutrition/iron: alpha-1 antitrypsin, ferritin, folate, iron, transferrin, vitamin B12, vitamin D 25-OH D2/D3/total, vitamin D 1,25-(OH)2.
  • Enzymes: alkaline phosphatase, ALT, amylase, AST, GGT, LDH, lipase.
  • Additional labs: specialized laboratory and therapeutic-drug monitoring conversions. Use the Find a conversion box to locate a specific analyte quickly.
General unit conversions
  • Mass/weight: mg, g, kg, oz, lb
  • Length: mm, cm, m, in, ft
  • Volume: mL, L, tsp, tbsp, fl oz, cup
  • Temperature: Celsius and Fahrenheit
  • Pressure: mm Hg, Torr, cm H2O, kPa, PSI
The pressure conversions preserve the same unit set as the prior standalone pressure converter: mm Hg, Torr, cm H2O, kPa, and PSI.
References and formulas

Formula and reference notes are shown here so the conversion basis is visible on the page. For most linear laboratory conversions, the calculator uses: SI value = conventional value x conversion factor; to convert back, conventional value = SI value / conversion factor.

Conversion Formula or conversion note used by this calculator
Formula list loads with the calculator.
Source and formula references
  • Laboratory conversion factors:Christiansen S, Iverson C, Flanagin A, et al. AMA Manual of Style: A Guide for Authors and Editors. 11th ed. Oxford University Press; 2020. Accessed June 12, 2026. https://www.amamanualofstyle.com/
  • General SI unit style: National Institute of Standards and Technology. Guide for the Use of the International System of Units (SI), NIST Special Publication 811. NIST SP 811.
  • Molecular weight and unit equivalence: Common chemical analyte conversions are based on molecular weight or direct unit equivalence where applicable. Local laboratory conversion factors should be used when provided by the reporting laboratory.
  • HbA1c: NGSP/IFCC master equation: IFCC mmol/mol = (NGSP percent - 2.15) x 10.929; NGSP percent = (0.09148 x IFCC mmol/mol) + 2.152. NGSP IFCC conversion.
  • Temperature: F = (C x 9/5) + 32; C = (F - 32) x 5/9.
  • Pressure: Physical unit conversions include mm Hg, Torr, cm H2O, kPa, and PSI and preserve the units used in the prior Perinatology.com pressure conversion calculator.
  • D-dimer caution: FEU and DDU results are assay conventions and should not be interchanged unless the laboratory method specifies the relationship. The calculator separates FEU unit scaling only.
  • Assay-dependent hormones: Some hormone conversions, especially prolactin in mIU/L, can vary by assay calibration. Use the local laboratory conversion factor when provided.