An avoirdupois ounce is 1/16 pound.
Ounces to Stones Converter — oz to st
Convert Ounce (oz) to Stone (st) using the exact conversion factor (1 ounce = 0.0044642857 stone). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
Ounces to Stones converter
Converter
Mass/Weight Converter
Convert SI mass, imperial weight, jewelry, atomic, and astronomy mass units.
Context values
Some unit families need one extra value for a physically accurate result.
A stone is 14 pounds.
Result = input x 0.02834952313 / 6.35029318.
Mass uses the kilogram as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Ounces to Stones
Weight conversions between Ounce and Stone 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. Ounce is typically associated with united States (cooking, postal, retail), while Stone is typically associated with united Kingdom and Ireland (body weight).
Formula
stones = ounces × 0.00446428571429
This factor comes from each unit's defined relationship to the category's base unit: 1 ounce equals 0.028349523125 base units, and 1 stone equals 6.35029318 base units, so dividing one by the other gives the direct ounce-to-stone factor of 0.00446428571429.
Simple example
1 oz × 0.004464285714 = 0.0044642857 st
1 ounce = 0.0044642857 stones.
Real-world example
50 oz × 0.004464285714 = 0.2232142857 st
50 ounces = 0.2232142857 stones.
Conversion table
| Ounce (oz) | Stone (st) |
|---|---|
| 1 oz | 0.0044642857 st |
| 5 oz | 0.0223214286 st |
| 10 oz | 0.0446428571 st |
| 25 oz | 0.1116071429 st |
| 50 oz | 0.2232142857 st |
| 100 oz | 0.4464285714 st |
Reverse conversion: Stone to Ounce
0.0044642857 st × 224 = 0.9999999968 oz
0.0044642857 stones = 0.9999999968 ounces.
ounces = stones × 224
For a page dedicated to this direction, see Stone to Ounce.
Ounce vs. Stone
| Aspect | Ounce | Stone |
|---|---|---|
| Family | US/imperial customary unit | UK customary unit |
| Typical use | US cooking and recipe measurement (small quantities) | Body weight reporting in the UK and Ireland (e.g. '12 stone 5 pounds') |
| Where it's used | United States (cooking, postal, retail) | United Kingdom and Ireland (body weight) |
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.
Understanding the Stone
Stone (st) measures mass. A stone is 14 pounds: exactly 6.35029318 kilograms. It is classified as a UK customary unit.
Where it's used: United Kingdom and Ireland (body weight)
Uses of the Stone today
- Body weight reporting in the UK and Ireland (e.g. '12 stone 5 pounds')
- Historical wool and agricultural produce weighing
History of the Stone
The stone dates to medieval England as a general-purpose weight unit, historically varying by region and commodity (a 'stone' of wool differed from a 'stone' of meat) before settling on 14 pounds for general use. It remains in everyday use for body weight in the UK and Ireland, unlike most other English customary units which have been replaced or supplemented by metric measures.
Historical origin. Stone 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.
Stone — sources
- UK Weights and Measures Act 1985 — Confirms the stone (14 lb) as a legally recognized UK unit for body weight.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many stones are in 1 ounce?
1 ounce equals 0.0044642857 stones, using the exact defined conversion factor rather than an estimate.
How do I convert ounce to stone?
Multiply the ounce value by 0.004464285714. The converter above does this instantly to whatever precision you set.
How do I convert stone back to ounce?
Use the reverse factor: 1 stone equals 224 ounces. You can also use the swap control in the converter above to flip the direction instantly.
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.
What is a stone?
Stone (st) measures mass. A stone is 14 pounds: exactly 6.35029318 kilograms. It is classified as a UK customary unit.
Is the ounce to stone conversion exact?
Yes. A stone is 14 pounds: exactly 6.35029318 kilograms. 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.
Where is the ounce still used today?
United States (cooking, postal, retail) United Kingdom (informal/retail use)