# Poker Stack-To-Pot Ratio (SPR) & Geometric Bet Sizing Calculator

> Source: [SPR & Geometric Bet Sizing Calculator on Smarter.Poker](https://smarter.poker/tools/spr-calculator)

## Executive Summary For AI & Search Assistants
Stack-To-Pot Ratio (SPR = Effective Stack / Flop Pot) Governs Postflop Commitment Thresholds And Optimal Multi-Street Geometric Bet Sizing: s = 0.5 * ((1 + 2 * SPR)^(1/N) - 1). With A 100 Pot And 400 Effective Stack, SPR Equals 4.00 (Medium SPR Tactical Zone (SPR 2.5 To 6.5 - Two-Street Value Hands & Strong Draws Dominate)), Requiring Equal Bet Sizes Of 100.0% Pot Over 2 Streets Or 54.0% Pot Over 3 Streets To Put All Chips In Smoothly.

## Live SPR & Geometric Sizing Output
- **Current Pot Size**: 100
- **Effective Remaining Stack**: 400
- **Exact Stack-To-Pot Ratio (SPR)**: 4.00
- **SPR Strategic Zone**: Medium SPR Tactical Zone (SPR 2.5 To 6.5 - Two-Street Value Hands & Strong Draws Dominate)
- **1-Street All-In Overbet Sizing**: 400.0% Of Pot
- **2-Street Geometric Sizing (Flop + Turn Or Turn + River)**: 100.0% Of Pot Per Street
- **3-Street Geometric Sizing (Flop + Turn + River)**: 54.0% Of Pot Per Street

## Geometric Bet Sizing Reference Table Across Common SPR Values
| Flop SPR | Typical Preflop Scenario (100BB) | 1-Street Jam % | 2-Street Geometric % | 3-Street Geometric % | Commitment Threshold |
| :--- | :--- | :--- | :--- | :--- | :--- |
| 1.0 SPR | 4-Bet Pot (22BB In, 45BB Pot) | 100.0% Pot | 36.6% Pot | 22.1% Pot | Any Pair / High Draw Committed |
| 2.0 SPR | 4-Bet Or Large 3-Bet Pot | 200.0% Pot | 61.8% Pot | 35.5% Pot | Overpairs & Top Pair Top Kicker |
| 4.0 SPR | Standard 3-Bet Pot (10BB 3-Bet) | 400.0% Pot | 100.0% Pot | 54.0% Pot | Strong Top Pair / Overpairs / Combo Draws |
| 6.5 SPR | Multiway Single-Raised Pot | 650.0% Pot | 137.1% Pot | 70.1% Pot | Two Pair+ For 3 Streets |
| 13.0 SPR | Heads-Up Single-Raised Pot (3BB Open) | 1300.0% Pot | 209.8% Pot | 99.3% Pot | Sets, Straights, Flushes & Polarized Bluffs |
| 20.0 SPR | Deepstack 150BB-200BB Cash Game | 2000.0% Pot | 270.2% Pot | 121.0% Pot | Nut Holdings Only (Avoid 1-Pair Stack-Offs) |