Apothecary, Avoirdupois and Household Measures
Converts grains, scruples, drams, apothecaries ounces, minims, fluid drams, fluid ounces, spoons and cups to metric.
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Example
- Quantity
- 5
- Unit to convert from
- Grain
Result: 5 grains = 323.99455 mg.
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What you enter
- Quantity
- Unit to convert from
How this is calculated
Citation
NIST Handbook 44 (2026), Appendix C, General Tables of Units of Measurement: 1 grain = 64.79891 mg exactly; 1 fluid ounce = 29.57353 mL. 21 CFR 101.9(b)(5)(viii) for the food-labeling values (teaspoon 5 mL, fl oz 30 mL, cup 240 mL). Read the sources: NIST Handbook 44 ↗, 21 CFR 101.9 ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.