A pump sharing valve for a gas turbine engine fuel system includes a housing having multiple ports. A sleeve is arranged in the housing and includes an inlet window and first, second and third windows axially spaced apart from one another. A spool is slidably received in the sleeve and includes a diameter and first and second cylindrical portions. The first cylindrical portion selectively connects the inlet window to the second and third windows. The second cylindrical portion selectively connects the inlet window to the first window. The spool is movable between first and second positions relative to the first, second and third windows to regulate flow. The first and second cylindrical portions respectively includes first and second widths. A first ratio corresponds to the first width to the spool diameter and a second ratio corresponds to the second width to the spool diameters. The first ratio is between 1.83 and 1.93 and the second ratio is between 1.22 and 1.32.