Big O (5-Card Omaha Hi-Lo) Equity Calculator

Big O equity calculator. 5-Card Pot Limit Omaha Hi-Lo 8-or-Better. Calculate win rates for high and low hands with 5 hole cards. Free and mobile-friendly poker odds calculator.

The Ultimate Free Poker Odds Calculator

Get instant equity simulations for Hold'em, Short Deck, Omaha (PLO4/5/6/8), Big O, Double Board PLO, and ICM. Create shareable links for any poker scenario—fast, free, on any device.

Cheat Sheet

Big O (5-Card PLO Hi-Lo) Complete Guide

Big O is a 5-card Pot Limit Omaha Hi-Lo game. The fifth card creates a 66% increase in hand combinations compared to PLO8, fundamentally changing strategy. With 10 possible two-card combinations (vs. 6 in PLO8), average winning hand strength is significantly higher.

Must Use Two + Split PotYou receive 5 hole cards but must use exactly 2 from your hand and 3 from the board. The pot splits between best High and qualifying Low. You can use different card combinations for High and Low.
8-or-Better LowA Low hand only qualifies with 5 unpaired cards ranked 8 or lower. Ace plays as lowest (1). If no Low is possible, High scoops the entire pot. The 'Wheel' (A-2-3-4-5) is both the Nut Low and a strong High straight.
Scooping vs QuarteringScooping (winning both High and Low) is the primary goal. Getting 'Quartered' (tie for Low, lose High = 25% of pot) is a disaster. In Big O, with 5 cards each, quartering risk is even higher than PLO8.

Big O vs PLO8: Key Differences

Nut Inflation

In PLO8, top two pair might win. In Big O, sets are the minimum—often you need full houses or nut flushes. For Lows, naked A-2 gets quartered easily; protected Lows (A-2-3) are essential.

Variance Paradox

Despite seeming wilder, Big O can have lower variance for skilled players. Pre-flop equities run closer together, and bluffing is less effective since opponents likely 'have it' with 5 cards.

Dangler Death

A 'Dangler' is a useless 5th card (e.g., A-2-K-K-9 where 9 doesn't connect). In PLO8, you can hide a bad card. In Big O, every card must work together—danglers are devastating.

Starting Hand Tiers

Tier 1: Premium Scoop Monsters

Hands where all 5 cards interact perfectly to win both High and Low. These are raising hands from any position.

Tier 2: Strong Multi-way Hands

Solid hands for big pots but lacking absolute perfection. Play these in position or multi-way pots. Note: Bare A-A with poor side cards is dangerous in Big O.

Trap Hands to Avoid

Beginners lose the most with these. Naked A-2 (no backup) gets counterfeited. Middle rundowns can't make Nut Low. Non-nut Highs are expensive second-best.

Post-Flop Tips

Counterfeiting

When a board card pairs your Low card (e.g., you have A-2, board shows 2), your Low is ruined. Solution: Play hands with backups like A-2-3.

Open-Limping

Unlike Hold'em, limping can be valid in Big O—it keeps pots small with drawing hands and invites profitable multi-way action.

Fold the Second Nut

With 5 cards per player, someone likely has the absolute nuts. K-high flush or non-nut straights facing heavy action should fold.

Core Strategy Principles

1. Prioritize Scoop: Never play for just half the pot. 2. Respect the 5th Card: Assume opponents are stronger than in PLO8. 3. Avoid Danglers: Don't play 4-card hands in a 5-card game. 4. Fold Second Best: In a game of nuts, second nuts is the first loser. 5. Backup Your Lows: A-2-3 beats A-2 when the board counterfeits.

Powerful Features

Share & Save Hand History via URL

Stop taking messy screenshots. With our Share feature, you can generate a unique URL for any poker hand scenario. Send it to friends, coaches, or forums to discuss strategy. They will see the exact board, player hands, and equity results instantly just by clicking the link.

Pro Tip: Setup Hands 10x Faster with Keyboard

Designed for PC users who demand speed. You can input entire hand ranges without touching your mouse. Use Arrow keys to navigate and simply type card codes to assign them instantly.

Quickly set cards (Rank + Suit)Type 'Ah', 'Td'...
Navigate between cardsArrow Keys
Clear cardBackspace / Delete

Get Instant Access from Home Screen

Enjoy faster access and offline capabilities by adding our tool to your home screen. It works just like a native app but lives in your browser without any installation process.

Frequently Asked Questions

How accurate is this calculator?

The results typically have a margin of error of under 0.5%, providing high precision for strategy decisions.

Why is this calculator so fast?

Unlike standard calculators that rely on heavy objects, our engine uses integer-based bitmasks and binary operations to evaluate hands in microseconds. By using reusable TypedArrays to eliminate garbage collection pauses and implementing optimized combinatorial logic, we achieve native-app performance directly in your browser.

How should I use this tool?

Use it to review your played hands. Check if you made the right decision by seeing your actual win chance in that spot. It's perfect for studying 'what-if' scenarios and learning how different cards affect your odds.

Does it work on mobile?

Yes, our interface is fully optimized for smartphones and tablets.

How many players can I calculate for?

You can simulate equity for up to 9 players at once.

Is it really free?

Yes, 100% free. No hidden fees, no credit card required, and no download needed.

Why do the results vary slightly?

We use Monte Carlo simulation to calculate odds instantly. Since this method uses random sampling for estimation, slight variations in the calculated values may occur.