Poker Open Raise Sizing: The Complete Position Guide
Last updated: May 12, 2026
Open raise sizing is the amount you raise preflop when first entering the pot. Modern GTO theory recommends a single standardized size per position rather than varying by hand strength — using the same size with aces and trash hands makes you unexploitable.
Online cash games have converged on 2.5bb from most positions, with 2–2.2bb from the BTN to keep the blinds in. Live cash games use 3–4bb to reflect the looser player pool and larger effective stacks. This page covers the optimal sizing formula by position, why limping is inferior, how stack depth modifies sizing, and the tournament vs cash game differences.
Why Open Raise Sizing Matters
Your preflop raise size sets the pot-to-stack ratio for every street that follows. A larger open creates a bigger pot relative to remaining stacks, which accelerates commitment thresholds and reduces post-flop manoeuvrability. A smaller open gives the blinds attractive pot odds to call with wide ranges, keeping you in multi-way pots more often.
Beyond pot geometry, sizing discipline is a privacy shield. If you raise larger with premium hands and smaller with speculative ones (or any detectable pattern), skilled opponents will adjust their ranges against you in real time. A locked-in size per position reveals nothing about your holding.
Pot odds for BB facing 2.5bb open:
Cost = 1.5bb (BB already posted 1bb)
Pot after call = 5bb total
Required equity = 1.5 ÷ 5 = 30% ... wait — pot is 2.5 + 0.5 + 1 = 4bb, call = 1.5bb → total 5.5bb
Required equity ≈ 1.5 ÷ 5.5 = 27%
The BB is getting roughly 3.7:1 on a call — a wide defense range is mathematically correct at this price.
Standard Sizing by Position (Online Cash)
Online cash games at $0.25/$0.50 through $5/$10 have largely converged on the following sizes. The BTN is the exception — opening smaller there keeps more players involved and leverages your positional advantage post-flop.
UTG
2.5bb
online
3–4bb
live
First to act. Tightest range; larger sizing common live.
HJ
2.5bb
online
3–4bb
live
Hijack. Similar sizing to UTG — still early position.
CO
2.5bb
online
3–4bb
live
Cutoff. Some solvers drop to 2.2bb online vs weaker pools.
BTN
2–2.2bb
online
3bb
live
Button. Smaller size keeps SB and BB in the pot.
SB
2.5bb
online
3–4bb
live
Small blind. Complete or raise; never limp vs BB alone.
These sizes assume a full 6-max or 9-handed table. Heads-up play compresses to 2–2.5bb from the SB (which is also the BTN). See preflop opening ranges for how range width interacts with sizing.
Live Cash Game Sizing Adjustments
Live poker environments differ from online in two important ways: players are generally looser (wider calling ranges) and effective stacks are typically deeper in big blind terms. Both factors push optimal sizing upward.
Looser calling ranges
Recreational players call with many more hands than GTO suggests. A 2.5bb raise will often see 3–5 callers. Raising to 4bb doesn't stop them from calling — but it makes each call more expensive and profits more per caller.
Deeper effective stacks
Live $1/$3 games often sit with $300–$500 stacks (100–166bb). Deeper stacks mean more implied odds for drawing hands, which incentivizes loose calls. Larger opens partially counteract this by raising the call threshold.
Fewer multi-way pot problems
A 3–4bb open doesn't eliminate multi-way pots in live games, but it does mean each caller is contributing more. When you do get called, the pot is healthier relative to your c-bet sizing.
Compare this to blind steal sizing from the BTN and CO where slightly larger sizes are also common live.
Tournament Open Raise Sizing
Tournament sizing evolves as the structure progresses. Three distinct phases apply:
Early Levels (No Antes)
2.5bb
Similar to online cash. Deep stacks, low pressure. Standard 2.5bb from most positions.
Middle Levels (Antes)
2–2.2bb
Antes pre-build the pot. A 2bb open is now risking 2bb to win ~3.5bb of dead money — excellent odds to steal.
Short Stack (<20bb)
Shove or fold
Traditional opens are replaced by shove-or-fold play. A 2.5bb open commits 12% of a 20bb stack — too much to fold post-flop.
How Stack Depth Changes Sizing
The deeper the effective stack relative to the big blind, the more important it is to keep sizing consistent. At 200bb effective, a 3bb open commits only 1.5% of your stack — the post-flop game drives outcomes. At 20bb effective, that same 3bb open commits 15% and should trigger a fundamentally different strategy. For more on managing stack depth decisions, see stack depth adjustments.
200bb+
2–2.5bb
Deep stack play. Post-flop skill edges dominate. Keep opens small to build playable pot sizes.
100bb
2.5bb
Standard online configuration. The benchmark sizing is calibrated for this depth.
40–60bb
2.5bb
Mid-stack. Effective stacks still deep enough for traditional open-raise play.
20–30bb
2–2.5bb or jam
Opens commit a significant portion. Mix traditional opens with shoves on your strongest hands.
<20bb
Jam
Shove-or-fold only. Minraise-folding is strategically incoherent at this depth.
Adding Limpers — The +1bb Rule
When players limp before you, your standard open size no longer charges them the right price. The pot is already inflated, and each limper is getting better odds to call your raise than they would cold-calling a standard open. The solution is the +1bb rule: add 1bb to your standard raise size for every limper already in the pot.
BTN standard open: 2.2bb
1 limper → raise to 3.2bb (2.2 + 1)
2 limpers → raise to 4.2bb (2.2 + 1 + 1)
3 limpers → raise to 5.2bb (2.2 + 1 + 1 + 1)
The rationale: each limper has already committed 1bb. By adding 1bb per limper, you're maintaining roughly the same pot-odds ratio for the limpers to call your raise as a cold-caller would face against a standard open. This is especially important in live games where limping is common. For deeper context on why limping is a losing strategy, read why limping is inferior.
Common Open Raise Sizing Mistakes
✗ Varying size by hand strength
Fix: Use one size per position across all hands. Balanced ranges are unexploitable; hand-strength-correlated sizes are an instant tell.
✗ Raising too small in multiway pots (live)
Fix: A 2.5bb open at a live table full of callers invites 4-way pots. Size up to 4bb live to charge callers appropriately.
✗ Ignoring the antes in tournaments
Fix: Dead antes change the effective pot odds. Once antes are live, drop to 2bb — the pot is already partially built for you.
✗ Not adjusting for limpers
Fix: Raising your standard size over limpers under-charges them. Apply +1bb per limper to maintain correct pot odds relationships.
✗ Opening traditionally with a short stack
Fix: At under 20bb, a traditional open commits too much to fold later. Switch to shove-or-fold to preserve your equity.
Definitions
Frequently Asked Questions
How much should you raise preflop in poker?
In online cash games, the modern standard is 2–2.5 big blinds from most positions. From the button (BTN), 2–2.2bb is common to incentivize the blinds to call and build a pot in position. In live cash games, use 3–4bb to account for looser player pools and the larger effective stacks relative to the stakes. The key principle is to pick one size per position and stick to it regardless of hand strength.
Why do most players use 2.5bb online?
2.5bb is the equilibrium open size that most GTO solvers recommend for online cash games. It risks enough to make the blinds' calls slightly –EV with marginal holdings while keeping pot-to-stack ratios manageable for post-flop play. Smaller than 2bb gives the big blind automatic odds to call almost anything; larger than 3bb bloats the pot without meaningful strategic benefit against competent opponents.
Should your raise size change based on your hand?
No — this is one of the most important sizing discipline rules. If you raise to 3bb with strong hands and 2.5bb with bluffs (or vice versa), observant opponents will exploit that tell immediately. Use a single standardized size per position across your entire range. This makes you balanced and unexploitable, forcing opponents to defend correctly against your whole range rather than yours specific holdings.
How does live poker sizing differ from online?
Live cash games standardly use 3–4bb opens because the player pool is looser, there are often multiple callers, and effective stacks measured in big blinds are typically deeper. A 2.5bb open at a $2/$5 live game with many recreational players will often face 4–5 callers, turning your raise into a limp re-raise situation. Sizing up to 3–4bb filters out the weakest calls and maintains better post-flop playability.
What raise size should you use in tournaments?
In the early levels of a tournament before antes are introduced, 2.5bb is standard. Once antes kick in, the pot is pre-built before anyone acts, making it correct to tighten up to 2–2.2bb to take advantage of the extra dead money. As the blinds escalate and stacks get shorter (under 20bb), shove-or-fold play replaces traditional open raises entirely. Adjust your sizing to the effective stack depth at the table.
How do limpers affect your open raise size?
When one or more players limp before you, apply the +1bb rule: add 1bb to your standard open size for each limper. If your normal BTN open is 2.2bb and two players have limped, raise to 4.2bb (2.2 + 1 + 1). This maintains the correct pot odds relationship and discourages the limpers from calling profitably with dominated hands. Simply raising to 2.2bb over limps gives everyone a cheap call.
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