An SPR calculator measures how deep you are once the flop comes down. With $180 behind and $22 in the pot, the stack-to-pot ratio is 8.2. The free calculator above shows what that means in bets: a two-thirds-pot bet on the flop and the turn, both called, still leaves about $132 behind for the river. That’s a medium-SPR pot, where one pair needs care and sets want to get it all in.
SPR calculator: what the number tells you
SPR = effective stack ÷ pot at the start of the flop. Effective stack means the smaller of the two stacks, because you can’t lose more than that.
| SPR | Pot type | Rough guide |
|---|---|---|
| Under 4 | Shallow | Top pair, good kicker is usually enough to get it all in |
| 4 to 10 | Medium | One pair plays for pot control; two pair and sets play for stacks |
| Over 10 | Deep | One pair is a bluff-catcher; draws and sets win the big pots |
These are guides, not laws. Board texture and your opponent count for as much.
Using SPR before the flop
SPR is something you choose. A 3-bet pot between two 100bb stacks often starts the flop around SPR 4, which is why overpairs are happy there. Flat-call a raise instead and the SPR is nearer 15, where the same pair of queens is much harder to play. Think about the hand you’ll hold on the flop, and size the pre-flop raise to set the SPR you want.
When the money goes in, the pot odds calculator checks your price and the poker odds calculator gives your equity. For tournament spots where ICM matters more than chips, see the bubble factor calculator.
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