Poker SPR Chart
Stack-to-pot ratio (SPR) tells you how many bets fit between the flop and a stack-off. This poker SPR chart lists geometric bet sizes for common SPRs so you can plan a two-street or three-street line that gets the money in. Pair it with the fold equity chart, the MDF chart, and the pot odds chart, or plug a spot into the free bluff calculator.
What SPR is
SPR = effective stack ÷ pot
Measure it at the start of the street — usually the flop, after blinds and raises are in. Effective stack is the smaller of the two stacks that can still go in. A $200 stack against $130 in a $10 pot is SPR 13, not 20. SPR is a depth rating: how many streets of betting can still happen before someone is all-in.
SPR chart: geometric bet sizes to get stacks in
| SPR | Bet size over 2 streets | Bet size over 3 streets |
|---|---|---|
| 1 | 36.6% | 22.1% |
| 2 | 61.8% | 35.5% |
| 3 | 82.3% | 45.6% |
| 4 | 100% | 54% |
| 6 | 130.3% | 67.6% |
| 8 | 156.2% | 78.6% |
| 10 | 179.1% | 87.9% |
| 13 | 209.8% | 100% |
| 20 | 270.2% | 122.4% |
| 30 | 340.5% | 146.8% |
Bet size is a fraction of the pot on each street. Formula: f = ((1 + 2·SPR)1/n − 1) / 2, with n = 2 or 3. Rounded to one decimal. Same SPR set used by common geometric-sizing references (1–30).
The formula
f = ((1 + 2·SPR)1/n − 1) / 2
Bet a constant fraction f of the pot and get called each street: the pot multiplies by (1 + 2f) every street. After n streets, stacks are in when (1 + 2f)n = 1 + 2·SPR. Solving for f gives the formula above.
Classic checks: at SPR 13, n = 3 gives f = 100% (three pot bets). At SPR 4, n = 2 also gives f = 100% (two pot bets).
Worked example: SPR 13 (deep, three streets)
Pot $10 on the flop. Effective stack $130. SPR = 130 ÷ 10 = 13.
- Plan: three pot-sized bets (100% each street).
- Flop: bet $10, call $10 → pot $30 ($120 behind).
- Turn: bet $30, call $30 → pot $90 ($90 behind).
- River: bet $90, call $90 → pot $270. Each has put in $130. Stacks are in.
That is why SPR 13 is the textbook deep-stack number: pot-pot-pot commits both players exactly. Prefer two streets? The chart says about 209.8% of pot each street.
Worked example: SPR ~4 (3-bet pot, two streets)
A 3-bet pot often lands near SPR 4. Pot $25, effective stack $100 → SPR = 4. Two-street geometric size is 100%: bet pot flop ($25) → pot $75; bet pot turn ($75) → stacks in. Over three streets, about 54% of pot each street leaves a river bullet. Low SPR does not mean always shove — it means one or two big bets finish the hand.
Practical SPR zones (rules of thumb)
Teaching bands, not solver law. Board texture still dominates.
- Low SPR (~≤4) — commit zone. One raise or two pot bets get stacks in. Strong made hands often play for stacks; thin bluffs need clear fold equity (see the fold equity chart).
- Medium SPR (~4–13). Room for flop + turn with a river decision, or a smaller three-street line. Many single-raised pots land here.
- Deep SPR (13+). Three streets fit. Pot-pot-pot at 13 is the clean commit line; deeper (20, 30) needs overbets to threaten the stack geometrically.
Facing a bet, pot odds and MDF still govern call/fold math — this chart only answers how large a planning size needs to be to threaten the remaining stack.
What the chart leaves out
Geometric sizing assumes you want stacks in. Dry boards with a capped range often want smaller sizes; nut-advantage boards can size larger off the geometric line. Raises multiply the pot faster than calls, and multiway pots change effective SPR per opponent. Semi-bluffs still need outs plus fold equity — use the calculator when the question is whether a barrel prints.
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See it on Amazon →SPR FAQ
What is SPR in poker?
SPR means stack-to-pot ratio: effective stack divided by the pot at the start of a street, usually the flop. SPR = effective stack ÷ pot. A $130 effective stack into a $10 pot is SPR 13.
How do you use SPR for bet sizing?
Geometric sizing picks one bet size (as a fraction of the pot) that, if called each street, gets the remaining stacks in over a chosen number of streets. The formula is f = ((1 + 2·SPR)^(1/n) − 1) / 2, where n is 2 or 3 streets.
Why is SPR 13 special?
At SPR 13, three pot-sized bets (100% of pot each street) get the stacks in exactly: pot goes 10 → 30 → 90 → 270 and each player puts in 130. It is the classic deep-stack three-street commit line.
What SPR is a commit zone?
As a rule of thumb — not GTO law — low SPR around 4 or less is often treated as a commit zone where one or two big bets get stacks in. Medium SPR sits between about 4 and 13. SPR 13+ is deep, with room for three streets of action.
Does geometric sizing mean you must bet that size every street?
No. It is a planning tool for how large a line needs to be to threaten the stack. Real hands still depend on board texture, range advantage, and whether you want to leave room behind. Use the chart as a baseline, then adjust.