Transmission coefficients for arbitrary potential barriers are obtained using a spreadsheet approach to solve the pertinent Schrodinger equation for the corresponding dispersion eigenfunctions in one dimension. Potentials should be of finite range, otherwise arbitrary. The method of implementation in personal computers is presented here, and it is also shown that the graphical capabilities of the software make it more useful in teaching. This approach reproduces exact solutions for square step barriers and it is illustrated with Gaussian potential energy functions. As a practical example, we simulate a chemical reaction whose rate shows an Arrhenius-like behavior.