For converting between different weight units, the weight converter tool is the best option. There is also a real-time weight conversion tool to help you convert between different units, such as pounds to kilograms, kilograms to pounds, and ounces to stones, etc. This article will also explain what weight is, whether it is a force, and even briefly touch on body weight, health issues, and how to lose weight (and gain weight) if you are interested. An object\'s weight is determined by the force of gravity pulling it down. Based on the mass of the object and the acceleration due to gravity, which is 9.8 m/s2 on Earth. Weight is calculated by the formula F = m * 9.8 m/s2, where F is the object\'s weight in Newtons (N) and m is its mass in kilograms.