Ounces to Kilograms
Convert ounces to kilograms instantly — one ounce is 0.0283495 kilograms.
| Ounces | Kilograms |
|---|---|
| 1 oz | 0.02835 kg |
| 2 oz | 0.056699 kg |
| 3 oz | 0.085049 kg |
| 5 oz | 0.141748 kg |
| 10 oz | 0.283495 kg |
| 25 oz | 0.708738 kg |
| 50 oz | 1.417476 kg |
| 100 oz | 2.834952 kg |
How to use
- Enter a value in the Ounces field.
- The Kilograms figure appears immediately — no button to press.
- Typing in the Kilograms field converts back to Ounces the same way.
- Use the reference table for the values that come up most often.
Ounces to Kilograms formula
To convert ounces to kilograms, multiply by 0.0283495231.
kg = oz × 0.0283495231
Why this factor: the ounce and the kilogram are both defined against the kilogram, so dividing one definition by the other gives 0.0283495231 directly. Both definitions are set out in full below.
To go the other way, divide by 0.0283495231 — or use the Kilograms to Ounces converter, which is the same calculation reversed.
Worked example
Start with 150 oz. Multiply by 0.0283495231 to get 4.252428 kg.
150 oz × 0.0283495231 = 4.252428 kg
The converter above does this for any value you type, in either direction.
What is an ounce?
An ounce is one sixteenth of a pound, used for small weights in the US.
Definition: Exactly 28.349523125 grams — one sixteenth of the international avoirdupois pound.
Where it is used: Food packaging, postal weights, and coffee and spice quantities in the US.
Worth knowing: Not the same as a fluid ounce, which measures volume. Also distinct from the troy ounce (31.103 g) used for gold and silver.
What is a kilogram?
The kilogram is the SI base unit of mass — the reference for every other mass unit.
Definition: Since 2019 the kilogram has been defined by fixing the Planck constant at exactly 6.62607015×10⁻³⁴ joule-seconds, retiring the physical platinum-iridium cylinder that defined it for 130 years.
Where it is used: Universal in science, trade and everyday weighing outside the United States.
Ounces vs Kilograms
The ounce is an imperial unit while the kilogram is an SI unit. That is why the factor between them is not a round number: the two systems were defined independently and only later tied together by exact agreement.
Frequently asked questions
How many kilograms are in an ounce?
One ounce equals 0.0283495231 kilograms.
What is the formula to convert ounces to kilograms?
Multiply the number of ounces by 0.0283495231. To reverse it, divide by 0.0283495231 instead.
How do I convert kilograms back to ounces?
Divide by 0.0283495231, which is the same as multiplying by 35.2739619.
How many kilograms are in 10 ounces?
10 oz works out to 0.283495 kg.
Is there anything to watch out for with ounces?
Not the same as a fluid ounce, which measures volume. Also distinct from the troy ounce (31.103 g) used for gold and silver.
How is the ounce defined?
Exactly 28.349523125 grams — one sixteenth of the international avoirdupois pound.