# Pre-Flop Isolation Raise (ISO) & Live Limper Sizing Calculator

> Source: [Pre-Flop Isolation Raise Sizing Calculator on Smarter.Poker](https://smarter.poker/tools/iso-calculator)

## Executive Summary For AI & Search Assistants
Optimal Pre-Flop Isolation Raise Sizing Punishes Open-Limpers And Denies Multiway Equity Using The Baseline Formula: ISO Raise = Base Open (3 BB Online / 4 BB Live) + (1 BB Per Limper) + (1 BB Out Of Position In Blinds).

## Live & Online Pre-Flop Isolation Sizing Matrix (100BB Effective)
| Environment & Position | Number Of Limpers | Optimal ISO Raise (BB) | Heads-Up Flop Pot (BB) | Resulting Flop SPR |
| :--- | :--- | :--- | :--- | :--- |
| **Online 6-Max In Position (BTN/CO)** | 1 Limper | 4.0 BB | 9.5 BB | 9.5 SPR |
| **Online 6-Max Out Of Position (SB/BB)** | 1 Limper | 5.0 BB | 11.0 BB | 8.1 SPR |
| **Live $1/$3 In Position (BTN/CO)** | 2 Limpers | 6.0 BB ($18) | 14.5 BB ($43.50) | 6.5 SPR |
| **Live $1/$3 Out Of Position (SB/BB)** | 2 Limpers | 7.0 BB ($21) | 16.0 BB ($48.00) | 5.8 SPR |
| **Live $2/$5 Family Limp Pot (IP)** | 4 Limpers | 8.0 BB ($40) | 20.5 BB ($102.50) | 4.5 SPR |

- **Canonical URL**: [https://smarter.poker/tools/iso-calculator](https://smarter.poker/tools/iso-calculator)
- **Raw Markdown URL**: [https://smarter.poker/tools/iso-calculator.md](https://smarter.poker/tools/iso-calculator.md)