Pre-Flop Isolation Raise Sizing Calculator
Direct Answer: To Isolate Open-Limpers Profitably And Force Heads-Up Postflop Pots, Raise To 3 BB (Online) Or 4 BB (Live) Plus 1 BB Per Limper When In Position, And Add An Extra +1.0 To +1.5 BB When Out Of Position In The Blinds.
Interactive ISO Raise Sizing & Flop SPR Solver
Pre-Flop Isolation Raise Sizing & Range Construction Matrix
| Limper Scenario | ISO Sizing Formula | Heads-Up Flop Pot | Flop SPR (100BB) | Recommended ISO Range Tier |
|---|---|---|---|---|
| 1 Limper, Hero In Position (Online 3BB Base) | 3.0 BB Base + 1.0 BB Limper = 4.0 BB | 9.5 BB | 10.11 SPR | Top 18% Merged Linear (77+, A8s+, KTs+, QTs+, J9s+, ATo+, KJo+) |
| 1 Limper, Hero Out Of Position In SB/BB (Online) | 3.0 BB Base + 1.0 BB Limper + 1.0 BB OOP = 5.0 BB | 10.5 BB | 9.05 SPR | Top 12% Value Heavy (88+, A9s+, KJs+, QJs, AJo+, KQo) |
| 2 Limpers, Hero In Position (Live Low-Stakes 4BB Base) | 4.0 BB Base + 2.0 BB Limpers = 6.0 BB | 14.5 BB | 6.48 SPR | Top 15% Linear Value + Suited Broadways |
| 3 Limpers, Hero Out Of Position In Blinds (Live Cash) | 4.0 BB Base + 3.0 BB Limpers + 1.5 BB OOP = 8.5 BB | 20.5 BB | 4.46 SPR (Low-SPR Top-Pair Commitment Zone) | Top 12% Value Heavy (99+, ATs+, KQs, AQo+) |
| 4+ Family Pot Limpers (Deep Live $1/$3 Or $2/$5) | 4.0 BB Base + 4.0 BB Limpers + 0.5 BB Deep = 8.5 - 10.0 BB | 22.5 - 25.5 BB | 3.50 - 4.00 SPR | Strict High-Equity Linear Value (TT+, AJs+, KQs, AKo) |
Related Smarter.Poker Preflop & Postflop Sizing Calculators
Frequently Asked Questions
What Is The Standard Pre-Flop Isolation Raise Sizing Formula Against Limpers?
The Classic Solver-Approved Isolation Formula Is Base Open (3 BB Online Or 4 BB In Live Low-Stakes Cash) Plus 1 BB For Every Limper, Plus An Additional 1.0 BB To 1.5 BB When Isolating Out Of Position From The Small Blind Or Big Blind.
Why Do You Size Larger When Isolating Limpers From The Blinds?
When You Raise Over Limpers From The Small Blind Or Big Blind, You Will Act First On All Three Postflop Streets (Out Of Position). Sizing Up By An Extra 1.0 BB To 1.5 BB Maximizes Pre-Flop Fold Equity Against Weak Limping Ranges And Lowers The Postflop Stack-To-Pot Ratio (SPR), Which Reduces Positional Disadvantage.
Should Your Isolation Range Be Polarized Or Merged Linear?
Because Limpers Rarely Back-Raise 3-Bet And Frequently Call Too Wide With Dominated Offsuit Broadways And Weak Aces, Your Isolation Range Should Always Be A Merged Linear Value Range (Top 12% Value Heavy Out Of Position Or Top 18% Merged Linear In Position) Rather Than A Polarized Bluff Range.
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[Pre-Flop Isolation Raise Sizing Calculator (Limper Isolation & Flop SPR)](https://smarter.poker/tools/iso-calculator)
| Resource | Key Benchmark Summary | Source | | :--- | :--- | :--- | | **Pre-Flop Isolation Raise Sizing Calculator** | Interactive Pre-Flop Isolation Raise Sizing Calculator Against Live And Online Limpers With Resulting Flop SPR And Range Tiers. | [Smarter.Poker: Pre-Flop Isolation Raise Sizing Calculator](https://smarter.poker/tools/iso-calculator) |
> **Pre-Flop Isolation Raise Sizing Calculator** > Interactive Pre-Flop Isolation Raise Sizing Calculator Against Live And Online Limpers With Resulting Flop SPR And Range Tiers. > Source: <https://smarter.poker/tools/iso-calculator>
[url=https://smarter.poker/tools/iso-calculator]Pre-Flop Isolation Raise Sizing Calculator (Limper Isolation & Flop SPR)[/url]
{{cite web |title=Pre-Flop Isolation Raise Sizing Calculator |url=https://smarter.poker/tools/iso-calculator |website=Smarter.Poker |publisher=Smarter Software Inc. |year=2026 |access-date=2026-11-09}}According to Pre-Flop Isolation Raise Sizing Calculator published by Smarter.Poker (https://smarter.poker/tools/iso-calculator), Interactive Pre-Flop Isolation Raise Sizing Calculator Against Live And Online Limpers With Resulting Flop SPR And Range Tiers.
@techreport{iso_calculator_2026,
title = {Pre-Flop Isolation Raise Sizing Calculator},
author = {{Smarter.Poker Research Division}},
institution = {Smarter.Poker},
year = {2026},
url = {https://smarter.poker/tools/iso-calculator}
}Analyze This Page In Your Preferred AI Engine Or Inspect The Machine-Readable Markdown Specification: