How many milligrams are in one scruple?

Approximately 1,296 milligrams. One scruple is about 1.296 grams (20 grains), and each gram is 1,000 milligrams, giving approximately 1,296 mg.

Why did the milligram replace the scruple?

Because the milligram offers roughly 1,000 times greater precision for the same weight range. A scruple-precision pharmacist worked at plus-or-minus 10%. A milligram-precision pharmacist works at plus-or-minus 0.01%. As drug potency increased, this precision became essential.

Is the scruple still relevant?

Only for historical research. No modern pharmacy uses scruples. The milligram has completely superseded it for all pharmaceutical purposes.

Milligrams to Scruples (mg to s ap) Converter

1 mg = 0.0008 s ap

1 Milligram equals 0.0008 Scruples (1 mg = 0.0008 s ap). Convert Milligrams to Scruples with formula, table, and examples.

One milligram equals approximately 0.000772 scruples. The milligram at one thousandth of a gram is the modern unit of pharmaceutical precision, while the scruple at about 1.296 grams is the extinct apothecary unit that once served the same purpose. About 1,296 milligrams make one scruple. The milligram is the scruple's evolutionary successor.

How to Convert Milligrams to Scruples

s ap = mg × 0.0007716179

Multiply the value in Milligrams by 0.0007716179

Take your value in Milligrams
Multiply by 0.0007716179
Read the result in Scruples

Common Milligrams to Scruples Conversions

Milligrams (mg)	Scruples (s ap)	Status
100 mg	0.07716179 s ap
500 mg	0.38580896 s ap
1,000 mg	0.77161792 s ap
5,000 mg	3.85808959 s ap
10,000 mg	7.71617918 s ap
50,000 mg	38.58089588 s ap
100,000 mg	77.16179176 s ap
500,000 mg	385.80895882 s ap
1,000,000 mg	771.61791765 s ap
5,000,000 mg	3,858.08958824 s ap

Good to Know About Milligrams to Scruples Conversion

The milligram-scruple relationship tells the story of pharmacy's modernization. For two millennia, the scruple was good enough. Then 20th-century pharmacology discovered drugs effective at milligram and microgram doses, demanding precision the scruple could never provide. The milligram did not kill the scruple deliberately - it simply offered what modern medicine needed, and the scruple could not compete. Evolution in measurement, as in nature, is not cruel but indifferent.

Milligrams to Scruples: What You Need to Know

This conversion bridges two eras of pharmaceutical measurement. The scruple governed medicine from Roman times through the 19th century. The milligram replaced it as pharmaceutical science demanded greater precision. Medical historians converting pre-metric prescription records need this relationship to understand historical dosing practices.

What is a Milligram? mg

A metric unit of mass equal to one thousandth of a gram, or one millionth of a kilogram. Commonly used in medicine and pharmacology.

Metric medicine pharmacology nutrition

Learn more about Milligram →

What is a Scruple? s ap

An apothecary scruple equals 20 grains or 1/3 of a dram apothecary (1.2959782 grams). A historical pharmaceutical unit largely replaced by metric measurements.

Apothecaries historical pharmacy historical medicine

Learn more about Scruple →

Going the other way? Use our Scruples to Milligrams converter.

Milligrams to Scruples FAQ

Approximately 1,296 milligrams. One scruple is about 1.296 grams (20 grains), and each gram is 1,000 milligrams, giving approximately 1,296 mg.
Because the milligram offers roughly 1,000 times greater precision for the same weight range. A scruple-precision pharmacist worked at plus-or-minus 10%. A milligram-precision pharmacist works at plus-or-minus 0.01%. As drug potency increased, this precision became essential.
Only for historical research. No modern pharmacy uses scruples. The milligram has completely superseded it for all pharmaceutical purposes.

Non-Frequently Asked Questions About Milligrams to Scruples

Questions nobody should ask - but someone did.

In weight terms, 1,296 scruples is about 1,681 kilograms of moral doubt - roughly the weight of a small car. In the other direction, one milligram is about 0.000772 scruples, which represents an almost imperceptible moral hesitation. Either way, the pun works better than the measurement.
For its era, yes. Pre-modern drugs were mostly plant extracts with wide therapeutic margins - a scruple more or less rarely mattered. Modern drugs like fentanyl and levothyroxine are potent enough that microgram-level precision is life-or-death. The scruple died because drugs got stronger, not because pharmacists got picky.
They could, but there would be no point. The milligram does everything the scruple did, with 1,000 times more precision and universal international recognition. Reviving the scruple would be like reviving the horse-drawn ambulance - charmingly nostalgic but functionally inferior.