Help with formula (simple)

[Marvo]

Hi All,

Could I have a quick bit of help with a formula?

I'm trying to work out the success rate for a football manager.
Each game is worth 3 points for a win and 1 for a draw so if the manager has been in charge for 55 games the maximum points he could have accrued is 165.
The manager in question has 23 wins (23 x 3) and 12 draws (12 x 1) so has accrued 81 points.
Shown as a percentage, the manager has a 49% success rate (81/165) however the return I have with the following formula is 441.82%.

=SUM(M27*3+N27)/B27*3

Could somebody show me where I'm going wrong please? Much obliged.