SPR (Stack-to-Pot Ratio)
SPR (stack-to-pot ratio) is the effective stack divided by the pot on the flop. It shows how committed you are and which hands can play for stacks.
SPR, or stack-to-pot ratio, measures how deep the stacks are compared with the pot. It is calculated on the flop by dividing the effective stack (the smaller of the two stacks still in play) by the size of the pot. SPR helps you plan the whole hand: it tells you roughly how many bets remain and how strong a hand needs to be to put all the chips in.
How to calculate SPR
SPR = effective stack ÷ pot size on the flop
Two examples with 100 big blind stacks, where the small blind folds preflop:
- Single-raised pot: the button raises to 3 and the big blind calls. The pot is 3 + 3 + 0.5 = 6.5 and each player has 97 left. SPR = 97 ÷ 6.5 ≈ 14.9.
- 3-bet pot: the button raises to 3, the big blind re-raises to 10, and the button calls. The pot is 10 + 10 + 0.5 = 20.5 and each player has 90 left. SPR = 90 ÷ 20.5 ≈ 4.4.
Same starting stacks, very different hands: the 3-bet pot is far closer to an all-in.
What different SPRs mean
| SPR | Typical situation | Practical meaning |
|---|---|---|
| Below about 3 | Short stacks, 4-bet pots | Top pair or an overpair is often happy to get all-in. |
| About 3 to 7 | 3-bet pots with normal stacks | Strong one-pair hands can often commit; plan sizing so stacks go in by the river. |
| Above about 10 | Single-raised pots, deep stacks | One pair usually wants a smaller pot; sets, straights and better want to build a big one. |
These bands are rules of thumb, not fixed laws. Opponent tendencies and board texture matter too.
Worked example: planning with SPR
You 3-bet A♠ A♣ and get called, creating the 20.5 pot with 90 behind (SPR 4.4). The flop is J♦ 7♣ 3♠. A plan of betting about half the pot on each street gets you there naturally: bet 10 (pot 40.5, 80 left), bet about 25 on the turn (pot 90.5, 55 left), and the remaining 55 on the river is well under the pot. Your overpair is comfortable getting all the money in.
Now imagine the same aces in a single-raised pot with an SPR around 15. If an opponent raises you on the turn and river with 97 big blinds at stake, one pair is in a much tougher spot, because a player with a set or two pair can win a huge pot from you.
Why SPR is useful
- Plan before you act. Decide on the flop whether you are willing to get all-in, rather than discovering it on the river.
- Pick hands preflop with SPR in mind. Small pairs and suited connectors gain value at high SPR, where implied odds are larger.
- Avoid awkward spots. Bet sizes that leave a tiny amount behind usually make the next decision obvious for both players.
Frequently asked questions
How do you calculate SPR in poker?
Divide the effective stack (the smaller stack still in the hand) by the size of the pot when the flop is dealt.
What is a good SPR for top pair?
As a rule of thumb, top pair is often comfortable getting all-in with a low SPR, roughly below 3 or 4. At high SPRs it usually prefers to keep the pot smaller.
Why does a 3-bet pot have a lower SPR?
More chips go in preflop, so the pot is bigger and the stacks behind are smaller, which lowers the ratio.
Related poker terms
- Effective Stack — The effective stack is the smallest stack among players in a hand: the most chips that can actually be won or lost between them.
- Implied Odds — Implied odds count the extra chips you expect to win on later streets when you hit, making some calls profitable despite poor direct pot odds.
- 3-Bet — A 3-bet is the first re-raise in a betting round. Preflop it's the re-raise of an open raise, because the big blind counts as the first bet.
- Overpair — An overpair is a pocket pair higher than every card on the board, such as Q-Q on J-7-3. It beats top pair but is still only one pair.
- Deep Stack — A deep stack is a chip stack that is large relative to the blinds, often 150 big blinds or more, allowing more postflop play and bigger implied odds.
- Short Stack — A short stack is a chip stack that is small relative to the blinds, often under about 20 big blinds, leaving little room beyond shoving or folding.