Quote Originally Posted by spoonitnow
In NLHE we're heads up on the turn, the pot is $15 and our opponent bets another $10. How much equity do we need against his range to call?
You don't need any equity, just click the damn call button if you have at least $10 left

But seriously, on the assumption that we won't have any further bets to call on the river, we're calling $10 to win $35 so we need something like 30%.

If we think our opponent will bet on the river, this obviously changes. Assuming we call $10 and our opponent then bets $x on the river, we need our equity against this range to be at least (10+x)/(35+x) to make a profit. Of course with the little information you give in your opening question we can't really give much of an answer since a lot of the factors we should consider aren't available to us such as implied odds or what our options are on the river (I'm assuming you care about the river, since you deliberately said we're on the turn )

Since you call it pot odds edition, I'll just say equity needed is:
(total bets we're calling)/(total bets we're calling + pot before we call the last bet)