Poker Stack-to-Pot Ratio (SPR) Calculator
Calculate poker SPR and get strategic guidance for any street.
Find shove, raise, and fold thresholds based on stack-to-pot ratio for tournament and cash games.
Stack-to-Pot Ratio (SPR)
SPR is one of the most important strategic concepts in no-limit poker. It tells you how committed you are to a hand based on remaining stack relative to the pot.
The formula: SPR = Effective stack / Pot size
Where “effective stack” is the smaller of the two players’ remaining stacks at the start of the street.
SPR strategic ranges:
| SPR | Strategy |
|---|---|
| Under 1 (committed) | Almost always all-in profitable with any pair or strong draw |
| 1-3 (low SPR) | Top pair / overpair commits; play it like a 1-bet game |
| 3-6 (medium) | Top pair good, set/two pair very strong, slowplay rarely |
| 6-13 (medium-deep) | Sets and two pairs are key; bluff catchers value strong |
| 13-20 (deep) | Stack and pot management critical; avoid coin flips |
| Over 20 (very deep) | Implied odds dominate; strategy shifts heavily to position |
Why SPR matters:
- Commitment math: at SPR < 4, top pair often pot-commits
- Bluff frequency: higher SPR = more room to bluff or fold
- Stack preservation: deep SPR rewards postflop skill
- Tournament ICM: high SPR + bubble = tighten up significantly
Practical example: You raise to 3bb preflop with KK, called by one player. Pot = 7bb (3+3+1 from BB).
If both players have 100bb starting stacks, after preflop:
- Effective stack = 97bb
- SPR = 97 / 7 ≈ 14
This is “deep” — KK should bet small to medium, NOT shove. There’s plenty of room to extract value street-by-street.
If both players have 30bb (short stack):
- Effective stack = 27bb
- SPR = 27 / 7 ≈ 4
Now KK should be ready to commit on the flop with any non-A flop — there’s not enough room to maneuver, so just get money in.
Common SPR ranges by game:
| Game Type | Typical SPR Range |
|---|---|
| Tournament early (100bb starting) | 10-30 preflop, 5-15 by river |
| Tournament middle (30-50bb) | 4-10 preflop |
| Tournament late (15-25bb) | 1-3 preflop — push/fold range |
| Cash 100bb | 10-25 |
| Cash 200bb (deep) | 25-100+ |
| Cash 50bb (short) | 5-12 |
The “20-1” rule: Aim to 3-bet to 20% of effective stack when out of position to keep SPR around 4 — perfect for top-pair-or-better commitment. Smaller raises create awkward postflop SPRs.
Multiway considerations: SPR multiplies in multiway pots. With 3 players in a 21bb pot at 100bb stacks, “effective” SPR on flop drops because the next aggressor sets the price.
Mistake patterns by SPR:
Low SPR (under 4):
- Mistake: not commiting top pair
- Fix: any reasonable equity = jam
Medium SPR (4-10):
- Mistake: pot-committing with weak hands
- Fix: think 1-2 streets ahead about commitment math
High SPR (over 15):
- Mistake: getting all-in with one pair
- Fix: tighten up, focus on implied odds and big draws