Dear yashiro32,
(I presume that we are talking about RF PCBs), This said, there are definetly some 'standard' formulaes but then their "standardness" is quite relative, i.e, the formulas include/exclude few approximations which are directly application specific. If your application demands stringent performance, you can include/exclude them as appropriate.
You can easily find your application specific formulae from any book dealing on strip and microstrip designs. I shall soon uplink some shortly, or you can look in 'Attachments'.
Sai