Mass and Weight · Unit Converter

Convert Ounce to Kilogram

Convert ounces to kilograms instantly. 1 ounce = 0.0283495231 kilogram — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Kilogram to Ounce converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Dr. Ashok Kumar K, Ph.D.
Mass and Weight category 2 min read Published Last reviewed Updated

Units explained

Avoirdupois

Ounce

What is a ounce?

The (avoirdupois) ounce (oz) equals one-sixteenth of a pound, about 28.35 grams.

Origin of the ounce

From Latin 'uncia', meaning a twelfth part.

Where it is used

US food portions, postal weights, and boxing weight classes.

When and where it was developed

Standardized as 1/16 of the international pound from 1959.

Metric / SI

Kilogram

What is a kilogram?

The kilogram (kg) is the SI base unit of mass, defined by fixing the Planck constant h at 6.62607015E-34 J s.

Origin of the kilogram

From Greek 'khilioi' (thousand) plus 'gramma' (small weight).

Where it is used

The worldwide base unit of mass in science, commerce, and everyday life.

When and where it was developed

Adopted in 1795; redefined through the Planck constant on 20 May 2019.

Ounce to Kilogram conversion formula

The relationship between ounces and kilograms:

1 oz = 0.0283495231 kg
1 kg = 35.2739619807 oz

To convert ounces to kilograms, multiply the value in ounces by 0.0283495231. To reverse, multiply kilograms by 35.2739619807.

How to use this converter

Type a value into the calculator. The result in kilograms updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Kilogram to Ounce converter for the reverse direction.

Step-by-step: convert ounces to kilograms

  1. Write down the value in ounces (oz).
  2. Multiply that value by the factor 0.0283495231.
  3. The product is the equivalent value in kilograms (kg).
  4. To reverse, multiply the kilogram value by 35.2739619807.

Worked examples

Example 1 — Convert 1 oz to kg:
1 × 0.0283495231 = 0.0283495231 kg

Example 2 — Convert 100 oz to kg:
100 × 0.0283495231 = 2.83495231 kg

Real-world example — Furniture and large objects

A 72-ounce piece of furniture converts to a value in kilograms that's easier to mentally compare with room dimensions. This is the typical workflow when shopping internationally and product specs use a different unit than your room measurements.

72 oz × 0.0283495231 = 2.0411656632 kg

Real-world example — Children's height milestones

A 150-ounce-tall child measures a value in kilograms that's commonly used for theme-park ride height requirements when travelling between countries that use different measurement units.

150 oz × 0.0283495231 = 4.252428465 kg

Real-world example — Body height conversion

You enter your height as 180 ounces into an international job or visa application. The form then asks for the same value in kilograms — converting between these adjacent units is one of the most-used length conversions globally.

180 oz × 0.0283495231 = 5.102914158 kg

Ounce to Kilogram conversion table

Standard reference values for converting ounces to kilograms:

Ounce [oz]Kilogram [kg]
0.010.0002834952
0.10.0028349523
10.0283495231
20.0566990462
30.0850485693
40.1133980924
50.1417476155
100.283495231
200.566990462
300.850485693
401.133980924
501.417476155
1002.83495231
50014.17476155
100028.3495231

Frequently asked questions

How many kilograms is 1 ounce?
1 ounce equals 0.0283495231 kilogram.
How do I convert ounces to kilograms?
Multiply the value in ounces by 0.0283495231 to get kilograms.
How do I convert kilograms back to ounces?
Multiply the value in kilograms by 35.2739619807, or use the Kilogram to Ounce converter.
How many kilograms is 100 ounces?
100 ounces equals 2.83495231 kilograms, because 100 × 0.0283495231 = 2.83495231.

Convert Ounce to other weight units

Show all Ounce conversions
Metric / SI (18 units)
Avoirdupois (14 units)
Troy & Apothecary (10 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Force / Engineering (5 units)

Sources & references

Conversion factor (1 oz = 0.0283495231 kg) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.