How to work out bluff EV

To be able to calculate the EV for bluff, you need to estimate how big is your folding equity. And as you can't never be sure, it's always just an estimation.

In your example you are investing $1.15 to win $1.02. So you need to get all 3 opponents to fold at least 53% of time. If you count rake, it's higher. If you think that you will get folds 60% of time, your estimated EV is 7% of the pot.

That's why it is so important to bluff with hands that have some equity. Even backdoor stuff is useful, it increases your EV when opponents just call your bluff.

Btw, in your example that is horrible spot to bluff, as there has been raise before you.

WOW, that's a horrible hand!
In a 4-way pot with that flop, you really shouldn't raise nor bet.

Make sure there isn't any straight draw or flush draw out (then the probably will fold to a c-bet)
If there is a draw thich misses on turn, make sure to second barrel full pot size.
If there is a completed draw on flop bet 2/3 pot.
If a draw hit on turn and your opponent cold call your bet on flop, don't bet.

That's some basics, and i can promise you will be ev+ bluffing on the lower limits (just make sure there isn't some maniac or similiar at your table).

wow estimating % of folds is tough, especially in Omaha.

As for the hand it was a read specific scenario, i think my opponent worked out what i was doing by this time (he may have had the hand as well ♦)