Use these charts only as estimates. Weighting all depends on your body type, muscle/fat ratio, amount of food or liquids in your system, equipment you are wearing for this particular dive. You will notice that you need more or less air in your BCD on each dive.
 

                         Exposure Suit Type                                     Weight

1.    Swimsuit or dive skin                                                            1 to 4 Lbs.

2.    Thin (1/16" or 5 mm)  One-Piece                                           5% of Body Weight
       Wet suit - Shorties or Jump Suit

3.     Medium -  THickness (3/16" or 5 mm)                                  10% of Body Weight
        Two - Piece  Wet Suit

4.     Cold Water (1/4" or 7mm) Two-Piece                                   10% of Body Weight
        Wet Suit with Hood & boots                                                 Plus 3 to 5 Lbs.

5.      Neoprene Dry Suit                                                            10% of Body Weight
                                                                                                  Plus 7 to 10 Lbs.

6.     Shell-style Dry Suits*                                                            10% of Body Weight
        using Light Weight                                                                Plus 3 to 5 Lbs.
        Non - Foam Underware

7.     Shell- Style Dry Suits *                                                        10% of Body Weight
        using Heavy Weight                                                            Plus 7 to 14 Lbs.
        or Foam Underwear

8.     Conversion Estimates:

                                                            From Salt Walter                                  From Fresh Water
        Body Weight                                 to Fresh Water                                     to Salt Walter
                                                            Subtract                                               Add

        100 to 125 Lbs.                               4 Lbs.                                                         4 Lbs.
        126 to 155 Lbs.                               5 Lbs.                                                         5 Lbs.
        156 to 186 Lbs.                               6 Lbs.                                                         6 Lbs.
        187 to 217 Lbs.                               7 Lbs.                                                         7 Lbs.

9.     Other Conversions:
                 80 Cubic Foot Tank Air Consumption                                             Add    5 Lbs.
                 100 Cubic Foot Rank AIr Consumption                                          Add    8 Lbs.
                 Inlet Correction for Current                                                             Add    4 Lbs.