Computing the sum of a range based on a separate column with variable input values.

I am trying to solve for a range of numbers based on a value I choose. For example in Column A: I have a depth values in 0.05 m increments. I want to take a depth range from Column A (d-8b to d+4b, where d is depth and b is length value) then sum the cells in Column F that correspond to this range. d and b are in cells above the data so I can adjust them to suit my specific needs. I would like a cell that has a formula that gives me the sum of the values in column F that correspond to the depth range of d-8b to d+4b (from Column A). Please, if you have experience doing something like this, provide me with some insight. Please request clarification if my question is unclear. Thanks!