Stack-to-Pot Ratio (SPR): Planning Hands Before the Flop in 2026

Stack-to-Pot Ratio (SPR) is one number that tells you whether to commit all your chips or slow down. You calculate it on the flop by dividing your remaining stack by the size of the pot. The result tells you how many pot-sized bets are left to play with, and that single number changes how you should play almost every hand you are dealt.

Most players learn pot odds and implied odds early. SPR connects those concepts into a complete decision framework: it answers “should I be willing to put my entire stack in on this hand?” before you even see the flop. Once you understand SPR, you stop guessing and start planning.

This guide covers the formula, the four commitment zones every player should memorize, a breakeven equity table you can reference at the table, which hand types want which SPR, and how to set the right SPR through your preflop sizing. Everything is explained from scratch with no assumed knowledge.

What Is Stack-to-Pot Ratio (SPR)?

SPR compares your effective stack to the pot on the flop. The formula is:

SPR = Effective Stack ÷ Pot Size on the Flop

The effective stack is the smaller of the two stacks in the hand. If you have $500 and your opponent has $300, the effective stack is $300 because that is the most either player can win or lose. SPR always uses this number, not your own stack.

A high SPR (like 15 or above) means there is a lot of money behind relative to the pot, so you have room to maneuver across multiple streets. A low SPR (like 2 or 3) means the pot is already large compared to what is left, so you are close to committing your full stack on the flop. The number itself is the shortcut: it tells you how committed you are before any postflop action begins.

Three Quick Examples

All three examples assume 100bb effective stacks (the standard online buy-in) in a heads-up pot.

Notice how each extra preflop raise cuts the SPR dramatically. A single-raised pot gives you room for three streets of betting. A 4-bet pot leaves almost no room at all.

This is not a coincidence: preflop sizing is how you set your SPR, and the section on preflop manipulation later in this guide covers exactly how to use that.

The Four SPR Zones

Every flop SPR falls into one of four zones. Each zone tells you which hands are strong enough to stack off with and which hands should slow down. Memorize these four bands and you will have a ready-made plan for almost every postflop situation.

SPR 0 to 3: The Commit Zone

At SPR 3 or below, you are already committed. The pot is so large relative to what is behind that folding a strong one-pair hand is almost always a mistake. Top pair, overpairs (a pocket pair higher than any card on the board, such as Q-Q on a J-8-3 flop), sets, and strong draws should all go in on the flop.

Slow-playing in this zone wastes equity. With only one to three pot-sized bets remaining, every check gives your opponent a free chance to improve. Bet, raise, and get the chips in.

SPR 3 to 6: The Decision Zone

This is the grey area where hand reading earns its money. TPTK (top pair, top kicker: for example, holding A-K on a K-9-4 board) and overpairs are usually good enough to commit, but board texture and opponent tendencies start to matter.

On a dry board like K♦ 7♠ 2♣ (few draws possible), TPTK at SPR 5 is a comfortable stack-off. On a wet board like J♥ 10♥ 9♣ (many straight and flush draws possible), the same hand needs more caution because straights, flushes, and combo draws (a hand with both a straight draw and a flush draw at the same time) are all live. This is the zone where the standard 3-bet pot plays out at 100bb.

SPR 6 to 13: The Pot Control Zone

One-pair hands should bet once for value and then check. At these stack depths, committing with just top pair requires close to 47% equity against your opponent’s continuing range, and most top-pair hands fall short of that number against raises and multi-street aggression.

The stacking-off hands here are two pair or better: sets, straights, flushes, and strong combo draws with 12+ outs (cards remaining in the deck that complete your draw). For a full breakdown of how to manage pot size with medium-strength holdings, see our pot control guide.

SPR 13+: The Deep Zone

Deep stacks reward speculative hands and punish one-pair hands. Sets, disguised two-pair combinations, and nut draws with redraws (like a flush draw that also has a straight draw) are the only clean stack-off holdings.

Top pair at SPR 13+ becomes a one-street value hand. Bet the flop, check the turn, and evaluate the river.

Do not 3-bet the flop or commit across three streets with a single pair at this depth. The money you save by slowing down with marginal hands adds up fast over thousands of hands.

The Breakeven Equity Table

When all the money goes in on the flop, how much equity (your percentage chance of winning the hand at showdown) do you need for the call to break even? The answer depends entirely on SPR. The formula is:

Breakeven Equity = SPR ÷ (2 × SPR + 1)

You do not need to memorize the formula. Memorize the table instead.

How to Read This Table

The “You Risk” column is always equal to the SPR. At SPR 4, you are risking 4 pot-sized units to win a final pot of 9 units (your 4 + opponent’s 4 + the original 1 pot). That means you need at least 44.4% equity for the call to break even.

Two Takeaways Most Players Miss

This is exactly why one-pair hands lose their stack-off value as SPR increases. At SPR 2, top pair with a good kicker easily clears the 40% bar. At SPR 10, that same hand needs 47.6% and is facing a range that barely includes anything weaker than two pair.

Typical SPR by Pot Type

The table below shows the flop SPR you will actually see in standard 100bb cash game spots. Use it as a quick mental benchmark before you call or raise preflop.

These numbers shift in two common situations. Bigger open sizes (3bb or 4bb instead of 2.5bb) compress the single-raised pot SPR from ~17 down to roughly ~13 or ~10.

Shorter starting stacks (40bb in a tournament or 25bb in a Spin & Go) compress every row in the table by roughly the same proportion. Both scenarios are covered in the sections below.

Which Hands Want Which SPR

Different hand types perform best at different stack depths. Knowing which SPR your hand wants is what connects the zone framework above to the preflop sizing decisions below. If you are building or refining your opening ranges, this table explains why certain hands belong in 3-bet pots and others belong in flat-call lines.

Why Small Pairs Need Deep Stacks

Pocket pairs flop a set (three of a kind using both hole cards) only 11.8% of the time. That means you miss roughly 7 out of 8 flops. To make calling a raise profitable, you need to win enough on the 1 in 8 flops where you hit to cover the 7 times you fold, and that requires deep stacks and a high SPR.

At SPR 15+, the potential payout is large enough to justify the call. At SPR 4 (a typical 3-bet pot), there is not enough money behind to recover from the 88% miss rate. This is why flatting small pairs against 3-bets is usually a losing play at 100bb.

Why AA and KK Want Low SPR

Premium pairs almost always flop just one pair. One pair is strong enough to commit at low SPR (the Commit and Decision zones) but becomes a marginal hand at SPR 13+ where opponents only stack off with two pair or better. This is the main reason AA and KK should 3-bet preflop: it compresses SPR into the zone where their hand is strongest.

Flat-calling with AA to “trap” creates exactly the wrong SPR. You end up in a single-raised pot at SPR 17 with a hand that plays best at SPR 4.

How to Set SPR With Preflop Sizing

SPR is not something that just happens to you. You set it before the flop through your open size, whether you 3-bet or flat-call, and how large your 3-bet is. Matching your sizing to your hand type is one of the most practical skills in this entire guide.

Three Sizing Levers

Live Straddles Change Everything

In live cash games, a straddle (a voluntary blind, usually 2x the big blind, posted before the cards are dealt) inflates the preflop pot and cuts your effective SPR by more than half. If you normally play $1/$2 with a $200 stack, your preflop SPR is roughly 67. Add a $4 straddle and it drops to about 29.

Every pot type shifts down accordingly, so when a straddle is on, treat your stack as if it were half its usual depth. Tighten your speculative calling range and increase your 3-bet frequency with premiums. For a full breakdown of how sizing decisions carry through the rest of the hand, see our bet sizing guide.

SPR in Tournaments and Short Stacks

Tournament SPR compresses for three reasons that do not exist in cash games:

Two Quick Tournament Examples

At 40bb with antes, a standard open plus one caller already puts you in the Decision Zone. Top pair is a stack-off hand.

At 10bb, any raise and call creates SPR below 2, which means every flop decision is a commitment decision. This is exactly why push/fold charts dominate short-stack tournament play: there are no postflop decisions left to make. Our ICM guide covers how chip value changes near pay jumps and how to adjust your commitment thresholds.

Spin & Go Starting Stacks

Most Spin & Go formats start at 25bb. A standard 2.5bb open plus one call produces a flop pot of roughly 5.5bb with 22.5bb behind, giving you SPR ≈ 4.

That is the Decision Zone from hand one. Top pair and overpairs are commitment hands from the very first deal, which is why Spin strategy looks so different from deep-stacked cash games.

For the full stage-by-stage breakdown of how stack sizes change your strategy across an entire tournament, see our tournament strategy guide.

Five Common SPR Mistakes

Most SPR errors come from ignoring the number entirely and playing on autopilot. These five cost players money at every stake.

Every mistake on this list comes back to the same root cause: not knowing (or not checking) the flop SPR before making a decision. Build the habit of estimating SPR during the preflop action, before the flop even lands. Within a few sessions, the number will appear in your head automatically.

Worked Hand Example: 3-Bet Pot at SPR 4

This hand shows SPR in action from preflop planning through to a final decision. Every choice follows directly from the SPR calculated before the flop was dealt.

The Setup

$1/$2 cash game, 100bb effective. Cutoff opens to $6 and you 3-bet to $20 from the button with A♣ K♥. Blinds fold and cutoff calls.

Pot on the flop: $43 ($20 + $20 + $1 small blind + $2 big blind). Your remaining stack: $180.

SPR = $180 ÷ $43 ≈ 4.2 (Decision Zone)

Before the flop is even dealt, you already know: if you flop top pair or an overpair on a safe board, you are committing your stack. That is what SPR 4 means.

The Flop

Flop: K♦ 9♠ 4♥

You have top pair, top kicker on a dry, rainbow board (three different suits, so no flush draw is possible). This is the best possible scenario for TPTK at SPR 4, so when cutoff checks, you bet $25 into $43.

Cutoff check-raises to $75.

The Decision

Many players panic here. A check-raise looks strong and their instinct says slow down. But the SPR already answered this question before the flop.

At SPR 4.2, you need 44.4% equity to commit (from the breakeven table). TPTK on K♦ 9♠ 4♥ has roughly 65% to 75% equity against a typical check-raising range that includes sets, two pair, strong draws, and some bluffs. You clear the threshold by a wide margin.

You jam all in. The plan was set before the flop. The check-raise did not change it.

Frequently Asked Questions