The weight will be 6.803886 Kg

A pound is approximately .454 kilograms, so a 15 pound turkey has weight in kilograms of

(15 lb)*(.454 kg/lb) = 6.80 kg

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Strictly speaking, it is a weight of 6.8 kg-force, a unit that takes the Earth's gravity into account. A kilogram is the international unit of mass. Conversion of force (weight) to mass involves the value of the acceleration due to gravity. The mass of a 15-pound turkey will be different depending on where you weigh it. If your scale is on the moon, it will take quite a bit more mass to register a 15 pound force.

(15 lb)*(.454 kg/lb) = 6.80 kg

_____

Strictly speaking, it is a weight of 6.8 kg-force, a unit that takes the Earth's gravity into account. A kilogram is the international unit of mass. Conversion of force (weight) to mass involves the value of the acceleration due to gravity. The mass of a 15-pound turkey will be different depending on where you weigh it. If your scale is on the moon, it will take quite a bit more mass to register a 15 pound force.