Who needs a spreadsheet, just use 3rd grade math...
check out this thread
http://www.therxforum.com/showthread.php?t=492641
If -1 is a favorite........Unit size/(RL decimal +1) Bet this amount to win on the ML and risk this amount on the RL
For example, your unit size is $50, and the best you can find on the -1.5 is +130. 50/2.3=21.74........so you risk $21.74 on the RL, and bet to win $21.74 on the ML. The two bets can be at different books, depending on who has the best line for both.
Friends don't let friends bet the -1 line at Pinnacle. They will rip you off 3 cents every time, and that is just using their own lines, and not shopping both the ML and the -1.5 around. This is an easy shortcut that eliminates almost all the math.