A numerical method developed originally fur calculating the edge-induced relaxation of film stress in a semi-infinite thin film, and the corresponding stresses induced in the substrate, is extended to apply to stripes of finite width 21 and thickness h. Values of relaxation are obtained by numerical integration fur several values of the ratio R = Kl/h (K depends on the elastic constants of the film and substrate). Since numerical integration is necessary to evaluate rile full solution for each value of R, an approximate expression for the relaxation is derived. This expression is accurate to within 6% for R = 1 and the accuracy increases rapidly as R increases; becoming practically zero for R > 3. Since all substrate stress components depend uniquely on the film relaxation, they can also be calculated using this expression, It is shown that earlier expressions used for the finite stripe give very large errors both in the stripe and in the substrate. A method to extend the use of this expression to calculate stresses in an array of stripes separated by valleys and in the substrate under the array is also described. The expression is compared with experimental results on GaAs stripes grown on Si substrates.