Oz to Kg Converter: Ounces to Kilograms

How to use the ounces to kg converter

1. Enter a value in the Ounces field to convert oz to kg, or in the Kilograms field to convert kg to oz.
2. The result updates automatically as you type.
3. Use the output values for shipping labels, recipes, or scientific calculations.

How the oz to kg conversion works

The international avoirdupois ounce is defined as exactly 0.028349523125 kilograms. This factor comes from the definition of the pound (exactly 0.45359237 kg) divided by 16 ounces per pound. To convert ounces to kilograms, multiply the ounce value by this constant:

kg = oz x 0.028349523125

For example, a 16 oz bag of coffee weighs 16 x 0.028349523125 = 0.45359237 kg, which is exactly one pound.

To go the other direction and convert kg to oz, divide by the same factor or multiply by its reciprocal (approximately 35.27396):

oz = kg / 0.028349523125

Common ounces to kilograms reference values

This table lists frequently used conversions from ounces to kilograms, rounded to six decimal places for readability.

Because 16 oz equals exactly 0.45359237 kg, you can use that as an anchor point when estimating larger weights.

Avoirdupois ounces vs fluid ounces

This converter handles avoirdupois ounces, the standard unit of mass used in the United States for groceries, postal items, and body weight. A fluid ounce measures volume, not mass, and depends on the density of the liquid. For example, one fluid ounce of water weighs about 1.043 avoirdupois ounces at room temperature.

If you need to convert liquid volumes rather than mass, use a dedicated volume tool such as liters to ounces, quarts to oz, or pints to oz. Mixing up mass ounces and fluid ounces is one of the most common mistakes in cooking and shipping.

Practical uses for converting ounces to kilograms

International shipping carriers require package weights in kilograms, while many US scales display ounces. Converting oz to kg accurately avoids surcharges or rejected parcels. In nutrition and fitness, food labels outside the US list serving sizes in grams or kilograms, so converting helps track intake precisely. If you are working with smaller metric units, you might also find it useful to convert grams to kg after finding the gram equivalent.

Scientific work demands exact conversion factors rather than rounded approximations. Using the precise factor of 0.028349523125 ensures that repeated calculations do not accumulate rounding errors across large datasets.

Related weight conversions

The ounce sits within a broader system of imperial and metric weight units. Sixteen ounces make one pound, and converting larger imperial weights to metric often requires going through kilograms first. For heavier loads, you may need to convert kg to lbs or check tons to kg.

When breaking down ounces into pounds and remaining ounces, a dedicated ounces to pounds and ounces tool saves manual division. All of these converters use the same underlying NIST SP 811 definitions to guarantee consistency across units.

Worked examples