About {25 lb | 10 kg} is the lift you need with your buoyancy aircell (called a 'wing') for single tank diving, assuming you are properly weighted with a modern cylinder. Manifolded doubles require about {45 lb | 20 kg} of lift. If you need more lift then you are diving a giant old Heiser/Beauchat cylinder or you are diving steel doubles with several stage bottles, otherwise you probably need to "get the lead out". These are just approximations because the cylinder sizes, types and configurations, not lift capacity and not body weight, is the best guide to selecting the correct wing. We have more information in our article Suggestions for Selecting a Wing.