Apothecaries’ weight converter
Read historical English-language mass records in grains, scruples, drams, ounces and pounds with metric equivalents. Uses the English/U.S. apothecaries’ mass table, not fluid measures, avoirdupois weights or other countries’ systems.
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How it works
Formula
- 1 ounce = 480 grains; 1 pound = 5,760 grains
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Your result
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Sources
- NIST Handbook 44 — Appendix C, apothecaries units of massSources reviewed: 2026-10-30
- NIST — SI conversion factorsSources reviewed: 2026-10-30
Assumptions and limitations
Uses the English/U.S. apothecaries’ mass table, not fluid measures, avoirdupois weights or other countries’ systems. For historical study only; never use old recipes to determine medicine doses.
How to use this tool
Set up the inputs
Identify the mass system in your source before entering the value and selecting both units.
Worked examples
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Read an apothecaries’ ounce in several units
1 oz ap = 8 dr ap = 24 s ap = 480 gr = 31.1034768 g.
Frequently asked questions
How should I read the result from Apothecaries’ weight converter?
The ounce here contains 480 grains; it is not the common household ounce. The breakdown helps compare the complete historical mass ladder.
Processing and privacy
The calculation or transformation runs in your browser. The tool does not send its input values or generated output to an application server. Loading a page still makes infrastructure requests; optional analytics and Google consent messages have separate controls.
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Help and feedback
Consult the linked sources for definitions and reference data. Contact Support if you have a question or notice a problem.
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