Preflop Raise Sizing: GTO Sizes for Every Spot
Most players know what to raise preflop. Far fewer know how much — and wrong sizing costs you money every single session. Here’s the complete guide to GTO preflop raise sizing, from open raises to 4-bets.
Why raise sizing matters more than most players think
Raise sizing is one of the highest-leverage decisions in poker — and one of the most misunderstood. Size too small and you give your opponents excellent pot odds to continue with dominated hands. Size too large and you fold out the hands you wanted to play against while bloating the pot in marginal spots.
GTO (Game Theory Optimal) strategy isn’t arbitrary about sizing. Solvers produce specific raise sizes because those sizes balance risk and reward optimally: they charge enough to make speculative calls unprofitable while not pricing out the dominated hands you want in the pot.
The good news: once you understand the logic behind GTO sizing, the numbers become intuitive. Position, stack depth, and game type drive almost every sizing decision you’ll face.
Standard open-raise sizes by position (6-max cash)
In 6-max no-limit hold’em — the most common online format — GTO solvers consistently recommend these open-raise sizes:
| Position | GTO Open Size | Why |
|---|---|---|
| UTG / LJ | 2.5x | Tight range needs less protection from callers |
| HJ (MP) | 2.5x | Similar logic; still early position |
| CO (Cutoff) | 2.5x | Standard; button alone remains |
| BTN (Button) | 2.5x | Widest range — size stays consistent |
| SB (Small Blind) | 3x | BB has closing action; need larger size to fold equity |
Notice that 2.5x is remarkably consistent across positions. This is intentional: using the same size in every position prevents your sizing from revealing information about your hand strength or range. If you raise to 3x from UTG with AA and 2x with 22, a thinking opponent can exploit that pattern.
The small blind is the exception — raising to 3x is standard because the big blind has a significant incentive to defend (they’re already in for 1BB). A larger raise denies this equity more efficiently.
Practice these sizes until they’re automatic. Preflop Wizard drills you on the right action — including sizing — in every spot.
9-max and live poker: sizing up
In 9-max games — more common in live poker and some online formats — open-raise sizes shift slightly larger:
- UTG through MP: 3x (more players left to act)
- CO and HJ: 2.5x–3x
- Button: 2.5x
- Small Blind: 3x–4x
The extra half-bet from early position in 9-max is justified because you have more players left to act — each one represents additional equity denied by a larger size. In full-ring, a UTG 2x open is simply too cheap for the button and cutoff to fold speculative hands.
In live games specifically, many players at low stakes deviate wildly — opening to 5x–7x with premium hands or min-raising with garbage. Against these players, you can often just call a bit wider and let them build pots for you. Don’t copy their sizing; exploit it.
How stack depth changes everything
Stack depth is perhaps the single biggest factor in preflop sizing decisions — especially in tournaments where effective stacks shrink as the blinds increase.
Standard GTO sizing applies. SPR (stack-to-pot ratio) is high enough that postflop play matters, so you don't need to bloat preflop.
Slightly larger raises help set up better postflop SPRs for value hands. 3-bet pots become very committed.
Min-raising and folding becomes awkward at this depth. Push/fold charts start applying for strong hands from some positions.
At 10–15BB effective, you should be either going all-in preflop or folding. Raising to 2.5x leaves you pot-committed anyway.
One practical rule of thumb: if a raise of 2.5x leaves you putting in more than 15% of your stack, consider whether you should just shove instead. Raising small and then folding to a 3-bet burns chips without the equity of a committed stack.
Lock in your preflop sizing
Reading about sizing is one thing. Having it become automatic under pressure is another. Preflop Wizard drills you on real spots until correct sizing is instinct.
3-bet sizing: in position vs. out of position
3-bet sizing has one of the clearest positional divides in all of preflop strategy. The rule is simple but important:
In position (IP 3-bet)
2.5–3x
the open raise
Example: BTN 3-bets CO’s 2.5BB open to 7–8BB.
Smaller size because you have a positional advantage — you don’t need to price opponents out as aggressively.
Out of position (OOP 3-bet)
3–4x
the open raise
Example: BB 3-bets BTN’s 2.5BB open to 9–10BB.
Larger size compensates for positional disadvantage — you need to reduce the SPR so postflop play is less complex.
The logic: when you’re out of position, you don’t want a bloated pot where you have to play a big pot without seeing the flop first. A larger 3-bet either takes the pot down preflop or creates a lower SPR that favors your stronger range.
When there are callers between you and the original raiser, add 1BB per caller to your 3-bet size. If CO opens to 2.5BB and BTN calls before you 3-bet from the BB, go to 11–12BB instead of 9BB. The extra dead money in the pot justifies a larger size to price out the calling ranges.
4-bet sizing
Once you get to 4-bet territory, pot sizes can get unwieldy fast. GTO sizing for 4-bets follows a similar IP/OOP logic:
- IP 4-bet: 2x–2.2x the 3-bet size
- OOP 4-bet: 2.2x–2.5x the 3-bet size
- At 100BB deep: Usually 20–25BB total into a ~10BB 3-bet pot
In practice, many players just look at how much is already in the pot and commit to going all-in if their 4-bet would put in more than 40% of their stack. A 4-bet to 25BB when 100BB deep leaves 75BB behind — you’re still technically not committed. A 4-bet to 30BB when 80BB deep effectively is committed (37.5% of stack in preflop).
When to deviate from GTO sizing
GTO sizing is your baseline — the unexploitable default. Against specific opponents, deliberate deviations can be highly profitable.
Against loose/calling station players: size up
If someone is calling 5x opens with K7o, raise to 5x when you have a strong hand in position. They’ll call the extra size with the same weak range, giving you more value. Don’t try to force a fold — just charge them more to make the mistake.
Against nits (tight players): size down slightly
A 2.5x from a nit-heavy table can become 2x if you’re steal-raising with a wide range on the BTN or CO. You’re not getting called anyway — why risk more? The smaller size still applies enough pressure to fold the blinds while risking less when called.
Against aggressive 3-bettors: don’t auto-size down
Some players think raising smaller will invite fewer 3-bets. It usually doesn’t — aggressive players will 3-bet regardless of your open size. Don’t let fear of 3-bets cause you to min-raise and create awkward pot-committed situations.
The 4 most common preflop sizing mistakes
1Varying size by hand strength
Use the same 2.5x from every position regardless of whether you have AA or 76s. Hand-reading opponents will notice if you consistently raise bigger with premiums.
2Min-raising preflop
A 2x open gives callers excellent pot odds and doesn't adequately deny equity. In 6-max cash, 2.5x is the standard floor. Only consider 2x at 25BB or less in tournament play.
3Massively oversizing 3-bets
Raising to 5x–7x the open raise with QQ is a classic mistake. Optimal 3-bets are 3–3.5x OOP or 2.5x IP. Larger sizes fold out weaker hands that you want to stack.
4Ignoring the rake
At micro-stakes online (NL5–NL25), rake meaningfully affects optimal sizing. Slightly larger open raises (3x from all positions) recoup more EV against the rake structure than GTO deep-stack sizing.
The fastest way to internalize correct sizing is reps. Preflop Wizard puts you in thousands of real spots and shows you the right action.
Squeeze sizing with callers in the pot
A squeeze is a 3-bet after an open raise and one or more callers. The extra dead money in the pot changes the math — and the sizing — significantly.
A standard formula: 3x the open raise + 1BB for each caller. If CO opens to 2.5BB and BTN calls, your squeeze from the SB should be approximately 3 × 2.5 + 1 = 8.5BB, or roughly 9BB. If two players called, go to ~10BB.
The logic: callers have wider ranges than the opener, but they’re also pot-committed to defend. Your squeeze must be large enough to fold out the opener’s continuing range, not just the callers’. Undersizing a squeeze is one of the most expensive preflop mistakes in multiway pots.
Quick reference: standard sizing cheat sheet
| Situation | Size |
|---|---|
| Open raise (6-max, any position except SB) | 2.5x |
| Open raise from SB | 3x |
| Open raise (9-max UTG–MP) | 3x |
| 3-bet in position | 2.5–3x the open |
| 3-bet out of position | 3–4x the open |
| 3-bet with 1 caller (squeeze) | 3x open + 1BB per caller |
| 4-bet in position | 2–2.2x the 3-bet |
| 4-bet out of position | 2.2–2.5x the 3-bet |
| Short stack (20BB) open | 2.5x or push |
| Short stack (10–15BB) open | Push/fold only |
Frequently asked questions
Should I always raise the same size regardless of my hand?
Yes — at the open-raise stage, using the same size with every hand in your range prevents opponents from reading your hand strength. This is the core of range-balanced play. Exceptions: deliberate exploitative adjustments against specific players who won't notice.
Is min-raising preflop ever correct?
In tournament poker at 20BB or less, min-raising can be strategically sound as it leaves less behind after a shove. In deep-stack cash games, min-raising gives callers 3:1 odds on a call — far too cheap. Stick to 2.5x+ in cash.
Why do some players raise to 4x or 5x preflop?
Most often it's a leak — either they're trying to 'protect' premium hands (unnecessary if you size the same every time) or they learned at loose-passive tables where bigger sizes were exploitative. Against good players, oversizing folds out the weak hands you wanted to play against.
How does rake affect preflop sizing?
At micro-stakes (NL5–NL25), the rake takes a larger percentage of small pots. Raising slightly larger (3x instead of 2.5x) helps build pots big enough that rake is a smaller percentage — and positions you to win larger pots when you have the best hand.
How can I practice getting preflop sizing right?
Repetition with feedback is the fastest path. Preflop Wizard puts you in thousands of real preflop spots, shows you optimal sizing, and explains the reasoning behind each decision. Available free on iOS and Android.
Lock in your preflop sizing
Reading about sizing is one thing. Having it become automatic under pressure is another. Preflop Wizard drills you on real spots until correct sizing is instinct.