Big O Calculator

What the game is

Big O is five-card Omaha Hi/Lo. Players receive five private cards and compete for high and qualifying low halves of the pot.

Rules of Big O

• Each player starts with five private cards, making Big O a five-card Omaha Hi/Lo game.
• The high hand uses exactly two private cards and exactly three community cards.
• The low hand also uses exactly two private cards and exactly three community cards, but it can use different private cards than the high hand.
• A qualifying low needs five different ranks that are eight or lower. Aces are low, and straights or flushes do not count against the low.
• If no low qualifies, the best high hand wins the whole pot.

Example calculations

• Enter A♣ 2♦ K♣ Q♦ J♠ against A♥ 3♥ 4♠ 5♠ T♦ on 8♣ 7♦ K♠ to compare nut-low strength, counterfeit risk, and high equity.
• Study scoop equity on low boards with flush or straight possibilities.
• Add dead low cards to see how often lows get counterfeited.

Strategy examples

• Strong Big O hands need coordinated high value and resilient low value.
• Use the calculator to avoid hands that are likely to get quartered.
• Study blockers because five private cards make removal effects important.

Calculator preview

Preview the Big O calculator

The Big O calculator link opens the full table view with Big O already selected, so you can move from the rules on this page straight into a real hand study.

Use it to enter the same kind of cards shown in the examples, adjust known board cards or dead cards when they matter, and see how each card changes the numbers.

For split-pot games, the results help separate high equity, low equity, and scoop potential instead of blending everything into one vague guess.

Clicking through is the fastest way to preview the real Big O calculator workflow before you start building your own examples.

Preview the Big O calculator

Screenshots

Big O FAQs