Reverse BMI Calculator
You know which BMI (body mass index) you want to achieve, and need to know at which weight that is? Use the app Reverse BMI Calculator.
Rather than calculating your BMI from your height and weight, it determines which weight is needed for a given BMI based on your height.
You are not limited to standard units. In the settings, you can choose other height and weight units, including stone.
Screenshot with height in feet and inch: