I thought I was doing pretty good with a spreadsheet but seems to be pretty basic compared to some on here
Simple stake * odds for the win column for me, then I use
https://www.aceodds.com/bet-calculator/accumulator.html to work out the each way bets and just manually put it in.
I also don't tally up the potential winnings beforehand. I'll keep a full record of the date, bet, odds, stake then leave the potential winnings and vs SP blank - fill it all in after the festival. Then keep a tally of my profit/loss for each year and the total since starting antepost.
Never filled in the potential winnings column since doing this. It's pretty clear what a lot of the bets could win me and i'll know easily roughly what needs to come in to break even and above for the year but I don't like to tally that all up until the race is done. Would rather the exact winnings are a surprise rather than on the eve before the festival see I
could win XXXXX only to win XX