An avoirdupois dram is 1/16 ounce.
Drams to Ounces Converter — dr to oz
Convert Dram (dr) to Ounce (oz) using the exact conversion factor (1 dram = 0.0625 ounce). See the formula, worked examples, conversion table, history, and common uses.
Drams to Ounces converter
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An avoirdupois ounce is 1/16 pound.
Result = input x 0.001771845195 / 0.02834952313.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Drams to Ounces
Weight conversions between Dram and Ounce come up constantly in everyday commerce, shipping, and cooking, since US packaging is usually labeled in pounds while most of the rest of the world uses kilograms. Specifically: An avoirdupois dram is 1/16 ounce, and an avoirdupois ounce is 1/16 pound.
Formula
ounces = drams × 0.0625
This factor comes from each unit's defined relationship to the category's base unit: 1 dram equals 0.00177184519531 base units, and 1 ounce equals 0.028349523125 base units, so dividing one by the other gives the direct dram-to-ounce factor of 0.0625.
Simple example
1 dr × 0.0625 = 0.0625 oz
1 dram = 0.0625 ounces.
Real-world example
50 dr × 0.0625 = 3.125 oz
50 drams = 3.125 ounces.
Conversion table
| Dram (dr) | Ounce (oz) |
|---|---|
| 1 dr | 0.0625 oz |
| 5 dr | 0.3125 oz |
| 10 dr | 0.625 oz |
| 25 dr | 1.5625 oz |
| 50 dr | 3.125 oz |
| 100 dr | 6.25 oz |
Reverse conversion: Ounce to Dram
0.0625 oz × 16 = 1 dr
0.0625 ounces = 1 dram.
drams = ounces × 16
For a page dedicated to this direction, see Ounce to Dram.
Understanding the Dram (dr)
An avoirdupois dram is 1/16 ounce.
Understanding the Ounce
Ounce (oz) measures mass. The avoirdupois ounce is 1/16 of a pound: exactly 28.349523125 grams. It is classified as a US/imperial customary unit.
Where it's used: United States (cooking, postal, retail) United Kingdom (informal/retail use)
Avoirdupois ounce vs. troy ounce. The everyday ounce (avoirdupois, 28.35 g) used for cooking and shipping is a different, smaller unit than the troy ounce (31.10 g) used for precious metals like gold and silver — this page uses the everyday avoirdupois ounce.
Uses of the Ounce today
- US cooking and recipe measurement (small quantities)
- US postal and shipping weight
- Precious metals (troy ounce, a related but distinct unit)
History of the Ounce
The ounce descends from the Roman 'uncia' (a twelfth part), inherited through medieval English weight systems; the avoirdupois ounce (for general goods, as opposed to the troy ounce for precious metals) became standard for everyday trade, fixed at exactly 28.349523125 g via the pound's 1959 international standardization.
Historical origin. Ounce was not the invention of a single named person; it developed through the process described above.
Ounce — sources
- NIST — International yard and pound (1959) — Basis for the modern ounce via the standardized pound.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many ounces are in 1 dram?
1 dram equals 0.0625 ounces, using the exact defined conversion factor rather than an estimate.
How do I convert dram to ounce?
Multiply the dram value by 0.0625. The converter above does this instantly to whatever precision you set.
How do I convert ounce back to dram?
Use the reverse factor: 1 ounce equals 16 drams. You can also use the swap control in the converter above to flip the direction instantly.
What is a dram?
Dram (dr) is a unit of mass/weight.
What is a ounce?
Ounce (oz) measures mass. The avoirdupois ounce is 1/16 of a pound: exactly 28.349523125 grams. It is classified as a US/imperial customary unit.
Is the dram to ounce conversion exact?
Yes. The avoirdupois ounce is 1/16 of a pound: exactly 28.349523125 grams. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between avoirdupois ounce vs. troy ounce?
The everyday ounce (avoirdupois, 28.35 g) used for cooking and shipping is a different, smaller unit than the troy ounce (31.10 g) used for precious metals like gold and silver — this page uses the everyday avoirdupois ounce.