This calculator calculates the amount of adjustment solution needed to be added to starting solution to obtain the final solution requirements. Volume or weight of solution may be used. Just click on the weight or volume button to change to volume or weight units (Click here for illustration). The calculator uses a table (see Examples) of concentration (% weight) and its equivalent density. Interpolation is used to compute density values that are between the values in the table. The density is then used to compute volume or weight as needed.