What is SPR (stack-to-pot ratio) in poker?
SPR is the effective stack divided by the pot on the flop. It tells you how committed you are: with a low SPR (under 4) one bet and a call puts most of the money in, so one-pair hands can play for stacks; with a high SPR (over 10) there's a lot of money behind, so you need a much stronger hand to commit.
Why it matters
SPR is the bridge between preflop and postflop. A 3-bet pot at 100bb has an SPR around 4 — top pair is often good enough to stack off. A single-raised pot at 100bb has an SPR around 13 — top pair should proceed with caution against big bets.
Planning the SPR is also a preflop skill: 3-bet with hands that want a low SPR (big pairs, AK), and flat-call with hands that want a high one (small pairs, suited connectors chasing implied odds).
The numbers
- At 100bb: a single-raised pot (2.5bb open, one caller, ~6bb pot) has an SPR of about 16; a 3-bet pot (~20bb pot) about 4; a 4-bet pot (~45bb pot) about 1.2.
- A common guideline: with SPR under 3, commit top pair; SPR 3–6, top pair with a good kicker or better; SPR above 10, two pair or better to stack off without a read.
Figures come from the same preflop charts and research data the rest of the site uses (charts last updated July 5, 2026); they change when that data does.
Type the bet and the pot; get the break-even equity and a call/fold verdict.
Common questions
How do you calculate SPR?
Divide the smaller of the two stacks (the effective stack) by the pot size at the start of the flop. 90bb behind with a 20bb pot is an SPR of 4.5.
Why does SPR matter?
It sets how strong a hand needs to be to get all the money in. Low SPR favors made hands like top pair and overpairs; high SPR favors hands that can make the nuts, like sets and suited connectors.
Is this your leak?
Seven real hands, four minutes. The quiz finds the one pattern costing you the most — free, no signup.
Find my leak →