1. Depending on whether you want to determine your safe limit using your age or your weight, click the corresponding rose 2.1 If you chose age, input your age using numbers, not words 2.2 If you chose weight, first choose whether you want to use pounds or kilograms for your weight (it will not be saved or viewed by anyone but the person standing behind you) 2.2.1 If pounds, input your weight using numbers, not words 2.2.2 If kilograms, input your weight using numbers, not words Your caffeine safe limit will either be printed on the screen or shown as a variable in the top-right corner of the screen.
Images taken from Google and edited appropriately
