VPA calculator button

I am trying to link 3 cells together so that when one cell is changed, the other two cells change accordingly.Capture.PNG
In the attached screengrab, are the three cells that I am trying to link. Currently, the only cell with formula, is "Females Placed", which is calculated by: "Bird area (m2)"*"Stocking Density (birds / m2)". Is there a way that I can link all three cells, so that I can change any two values at a time, and the third value is automatically calculated, i.e. when I change "Females Placed" and "Bird area (m2)", then a value for "Stocking Density (birds / m2)" is automatically calculated, or if I change "Stocking Density (birds / m2)" & "Females Placed", then "Bird area (m2)" is calculated. I initally thought of inserting three individual VPA calculator buttons?

With Helper Fields for the inputs and using conditional formatting It is not that difficult to do.

Please have Look at the attachment. When you fill to Field The Dirt wil Grey out And the result is calculated in the Field Next to it.
This Is A Basic Solution. With VBA it cloud be possible to insert formula or manual input in the same cell