What is SPR in poker?

SPR (Stack-to-Pot Ratio) is the ratio of the effective stack size to the pot size on the flop. It measures how deep-stacked players are relative to the pot and helps determine commitment thresholds for different hand types. A low SPR (under 4) favors top pair hands, while high SPR (over 13) favors speculative hands like draws and sets.

How do you calculate SPR?

SPR is calculated by dividing the effective stack remaining after preflop betting by the pot size on the flop. For example, if you have 85 big blinds remaining and the pot is 10 big blinds on the flop, your SPR is 8.5.

What SPR should I commit with top pair?

With top pair top kicker (TPTK), you can profitably commit at SPRs below 4. With top pair weaker kicker, aim for SPRs below 3. At higher SPRs, top pair becomes a marginal calling hand rather than a stacking hand.

Why is SPR important for poker strategy?

SPR helps you understand which hands are appropriate for stacking off. Low SPRs mean you need weaker hands to commit (top pair is strong), while high SPRs require stronger hands (sets, straights, flushes). Understanding SPR prevents over-committing with marginal hands and under-playing strong hands.

SPR Calculator: Stack-to-Pot Ratio & Commitment Threshold Analysis

Stack-to-Pot Ratio (SPR) is one of the most important concepts in no-limit Texas Hold'em strategy. This free calculator helps you determine commitment thresholds by analyzing how deep your effective stack is relative to the pot. Understanding SPR transforms post-flop decision-making from guesswork into a systematic framework for knowing when to stack off and when to fold.

Professional players use SPR analysis to plan hands before the flop even hits. By calculating SPR in advance, you can construct preflop strategies that create favorable post-flop situations for your intended holdings. This calculator makes that process simple and provides actionable recommendations for each SPR zone.

Calculate Stack-to-Pot Ratio

Enter your effective stack and pot size on the flop to calculate SPR and receive commitment guidance.

Effective Stack (BB)

The smaller stack between you and your opponent, in big blinds (remaining after preflop)

Pot Size on Flop (BB)

Total pot including preflop bets when the flop is dealt

Big Blind Size ($) - Optional

Enter BB size to see amounts in dollars

Low (0-4) Medium (4-13) High (13+)

Stack & Pot Analysis

Effective Stack: 100 BB

Pot Size: 10 BB

Pot-sized Bet Required: 10 BB

Remaining After Pot Bet: 90 BB

Commitment Recommendations

Strategic Guidance

Strategy guidance will appear here based on your SPR calculation.

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

SPR is the ratio of effective stacks to pot size on the flop, calculated simply as: SPR = Effective Stack / Pot Size. This single number tells you how committed you are to the pot before any post-flop betting occurs. The concept was popularized by Ed Miller, David Sklansky, and Mason Malmuth in their influential book "Professional No-Limit Hold'em," and has since become a cornerstone of modern poker strategy.

According to PokerNews strategy analysis, SPR helps answer the fundamental question: "What strength hand do I need to profitably get all-in?" At low SPRs, top pair becomes a stacking hand. At high SPRs, you need sets, straights, or better to justify committing your entire stack.

SPR Calculation Example

You open to 3BB, the big blind 3-bets to 10BB, and you call. The pot is 21BB (10+10+1 small blind). You have 90BB remaining. SPR = 90 / 21 = 4.3. At this medium SPR, top pair top kicker becomes a borderline stacking hand.

The Three SPR Zones

SPR creates distinct zones that dictate optimal strategy. Understanding these zones is essential for constructing proper post-flop plans, as detailed in research from Upswing Poker's strategy articles.

SPR Zone	Range	Commitment Hands	Characteristics
Low SPR	0 - 4	Top pair+, overpairs	High pair hands dominate. Sets overkill. Draws suffer from poor implied odds.
Medium SPR	4 - 13	Overpairs, two pair+	Transitional zone. Top pair becomes marginal. Sets very profitable.
High SPR	13+	Sets, straights, flushes	Speculative hands thrive. Top pair rarely worth full stack. Premium draws gain value.

Low SPR Strategy (0-4)

At low SPRs, the effective stacks are so shallow relative to the pot that high pair hands can profitably go all-in. With SPR under 3, even top pair weak kicker can be a stacking hand against most ranges. This zone frequently occurs in 3-bet and 4-bet pots, blind vs. blind confrontations, and short-stack tournament play. The strategic implication is clear: value high card hands, and avoid speculative holdings that need deeper stacks to realize their potential.

Medium SPR Strategy (4-13)

The medium SPR zone requires more nuanced decision-making. Top pair becomes a calling hand rather than a raising hand. Overpairs are strong but not invincible. This is the zone where hand reading matters most - you need to carefully assess whether your opponent's line makes sense for a value hand or represents a bluff. Sets, two pair, and straights become optimal stacking hands in this range.

High SPR Strategy (13+)

High SPR situations favor speculative hands: suited connectors, pocket pairs (for set mining), and suited aces. Top pair, even top pair top kicker, is a marginal holding not worth committing 100+ big blinds. According to Card Player Magazine's analysis, this is where implied odds calculations become crucial - you need to hit big to win big, but the deep stacks make that profitable.

How SPR Affects Hand Selection

Understanding SPR allows you to manipulate situations preflop to create favorable post-flop scenarios for your holdings. This is the essence of poker hand planning.

Hand Type	Preferred SPR	Reason
AA, KK	Low (0-6)	Want to stack off with overpair without needing improvement
QQ, JJ, TT	Low-Medium (2-8)	Strong but vulnerable to overcards at very high SPR
AK, AQ	Medium (4-10)	Need to hit to commit; too risky at low SPR, insufficient implied odds at high
Small Pairs (22-77)	High (13+)	Set mining requires deep stacks for profitable implied odds
Suited Connectors	High (13+)	Need deep stacks to realize equity when hitting draws and made hands

Using SPR in Pre-Flop Planning

Smart players consider SPR before they even see the flop. By adjusting your preflop sizing, you can create the SPR that best suits your hand:

With premium pairs (AA, KK): Consider 3-betting larger to reduce SPR, making it easier to stack off on most boards
With speculative hands: Keep pots small preflop to maintain higher SPR and better implied odds
In position with medium hands: Control pot size through flats rather than 3-bets to preserve maneuverability
Against loose opponents: Size up with strong hands to create favorable low-SPR situations where they make mistakes

Pre-Flop SPR Manipulation

You hold pocket Kings. Opponent opens to 3BB, and you have 100BB. If you 3-bet to 9BB and they call, the pot is 19.5BB with ~91BB remaining (SPR ~4.7). If you 3-bet to 12BB and they call, the pot is 25.5BB with ~88BB remaining (SPR ~3.5). The larger 3-bet creates a more favorable low-SPR situation for your overpair.

SPR and Implied Odds

SPR directly determines implied odds for drawing hands. The relationship is explained in detail by Two Plus Two's strategy forums: the higher the SPR, the more chips remain to be won when you complete your draw.

With a flush draw at SPR 3, you might only win 3x the current pot when you hit. At SPR 15, you could potentially win 15x the current pot. This math explains why suited connectors are profitable at deep stacks but unprofitable in short-stacked situations.

Use our Pot Odds Calculator alongside SPR analysis to determine whether calling with draws is profitable given the remaining stack depth. Our EV Calculator can then quantify the expected value of specific post-flop decisions.

SPR in Tournament vs. Cash Games

SPR dynamics differ between tournament poker and cash games:

Tournament Considerations

Blind levels increase, naturally reducing effective SPR over time
ICM pressure affects commitment thresholds - see our ICM Calculator
Antes reduce SPR further in the pot before flop action
Late stages often feature SPR under 5, making top pair very valuable
The M-Ratio Calculator helps identify when you're in low-SPR territory

Cash Game Considerations

Consistent stack depths maintain stable SPR calculations
Deep stack games (200BB+) create ultra-high SPRs where set mining thrives
Short-stack strategies purposely create low-SPR situations
Bankroll management affects willingness to play at various SPRs - see Bankroll Calculator

Common SPR Mistakes to Avoid

Overcommitting at high SPR: Stacking off with top pair at SPR 15+ is usually a significant mistake against competent opponents
Undervaluing hands at low SPR: Top pair in a 3-bet pot is often strong enough to go with - don't fold too easily
Ignoring SPR in preflop planning: Your 3-bet sizing should consider what SPR you want to create
Set mining at low SPR: Calling with small pairs at SPR 3 is often -EV because you can't win enough when you hit
Forgetting about stack-behind: SPR only works if you're actually willing to bet/call the remaining stack when appropriate

Frequently Asked Questions

What is a good SPR for poker?

There's no universally "good" SPR - it depends on your hand. Premium pairs prefer low SPR (under 6) while speculative hands prefer high SPR (over 13). The skill is in manipulating preflop action to create the SPR that suits your holdings.

How do you calculate effective stack for SPR?

Use the smaller stack between you and your opponent. If you have 100BB and villain has 75BB, the effective stack is 75BB. For multiway pots, consider the effective stack against the player most likely to stack off.

Should I always commit at low SPR?

Not always - even at low SPR, bottom pair or weak draws aren't worth committing. Low SPR simply means that stronger one-pair hands become stacking hands. Always consider hand strength relative to the board texture.

How does position affect SPR decisions?

Position amplifies the value of high SPR situations because you control the betting action. Out of position, medium hands struggle at high SPR. In position, you can pot-control or extract value more effectively.

Does SPR change during the hand?

Yes, SPR decreases as more money goes into the pot. A starting SPR of 10 might become SPR 5 after flop betting. You should recalculate SPR on each street for the remaining stack-to-pot dynamics.

Continue Your Poker Education

Bet Sizing Strategy - Master optimal sizing for value, bluffs, and protection based on SPR
Pot Odds Calculator - Calculate drawing odds alongside SPR for complete decision analysis
Expected Value Calculator - Quantify the profitability of commitment decisions
Hand Range Visualizer - Understand opponent ranges to refine commitment thresholds
Position Guide - Learn how table position interacts with SPR strategy
Betting Structures - Understand how bet sizing creates different SPR situations
Texas Hold'em Complete Guide - Master the fundamentals of no-limit strategy

Responsible Gaming Note

This calculator is provided for educational purposes to help understand poker mathematics and strategy concepts. SPR analysis is a framework for decision-making, but poker outcomes involve variance regardless of mathematical correctness. Never gamble with money you cannot afford to lose, and remember that understanding poker theory is separate from managing the psychological and financial aspects of playing the game.