Blackjack has one of the lowest house edges of any game on a casino floor, but that does not mean the odds are in your favour. The maths of blackjack is really the maths of a small, permanent advantage the casino keeps on every hand you play. Understand how that advantage is measured, and what makes it bigger or smaller, and you can tell a fair table from an expensive one before you ever place a bet. This page is the overview: it explains house edge, return to player (RTP), and probability in plain terms, shows what moves the numbers, and links down to the detailed guides in this section.
Key Points
- House edge + RTP = 100%. A 0.5% house edge is the same as a 99.5% return to player.
- Blackjack’s edge is not fixed. With basic strategy at a good table it can be about 0.4–0.5%; poor rules or play push it far higher.
- Payout matters most. Switching from 3:2 to 6:5 adds roughly 1.3–1.4 percentage points to the house edge.
- Fewer decks favour the player — single deck can reach about 0.17%, eight decks about 0.65% with the same rules.
- Blackjack beats slots on odds: around 0.5% edge versus roughly 2–15% for slot machines.
- The house always wins long term. These figures are long-run averages, not session guarantees.
House edge vs RTP: two ways of saying the same thing
Every casino game is built to return less than it takes in over the long run. Two numbers describe that:
- House edge is the percentage of each bet the casino expects to keep, on average, over a very large number of hands. A 0.5% house edge means that for every $100 wagered, the casino expects to keep about 50 cents in the long run.
- Return to player (RTP) is the mirror image: the percentage it expects to pay back. RTP and house edge always add up to 100%. A game with a 0.5% house edge has a 99.5% RTP.
Both figures are long-run averages produced by probability, not promises about your next session. Over an evening you might win or lose far more than the edge suggests; over hundreds of thousands of hands the real results grind toward the theoretical number. That is the single most important idea on this page: the house always keeps an edge over the long run, and no betting pattern or “system” removes it.
Blackjack is unusual because its edge is not fixed. It depends on the table rules and, crucially, on how well you play. Played with correct decisions at a good table, blackjack’s house edge can sit near 0.5% (about 99.5% RTP) — among the best odds in the building. Played carelessly at a poor table, the same game can cost several percent.
What the odds of a single hand look like
House edge is a long-run average, but it is built from the probabilities of individual events. A few numbers help set expectations for any hand you sit down to play:
- Being dealt a natural blackjack (an ace with a ten-value card) happens roughly 4.8% of the time — about once every 21 hands.
- The dealer busts (goes over 21) about 29% of the time when standing on soft 17, and marginally more often when hitting soft 17.
- Outcomes per hand, with correct basic strategy, work out to roughly a 42% chance of winning, a 9% chance of a push (tie), and a 49% chance of losing. Because pushes return your bet, your chance of winning a hand that is actually resolved is about 46%.
Those figures explain why blackjack feels close to even yet still favours the house: you win slightly less often than you lose, and the small gap is the edge. The 3:2 bonus paid on a natural is what claws most of that gap back for a skilled player — which is exactly why the payout matters so much. If you are new to the game, our guide to how to play blackjack walks through the hand-by-hand mechanics behind these odds.
What moves the house edge
Two blackjack tables in the same casino can offer very different odds. Four things move the edge more than anything else.
Number of decks
Fewer decks favour the player. A single-deck game played with perfect strategy can drop the house edge to around 0.17%, while an eight-deck shoe with otherwise identical rules sits closer to 0.65%. Extra decks slightly dilute the value of the cards already dealt, which is why casinos often prefer big shoes.
The blackjack payout: 3:2 vs 6:5
This is the biggest trap on a modern casino floor. A natural blackjack has traditionally paid 3:2 — a $10 bet wins $15. Many tables now pay 6:5, where the same $10 bet wins only $12. That single change adds roughly 1.3–1.4 percentage points to the house edge. A game that would cost about 0.4% at 3:2 can jump to well over 1.5% at 6:5, even with all other rules identical. Always check the felt for the payout before you sit down; a 6:5 table is far more expensive than it looks.
Dealer and table rules
Smaller rules add up. Rules that help the player include the dealer standing on soft 17, being allowed to double after a split, late surrender, and re-splitting aces. Rules that help the casino include the dealer hitting soft 17, restrictions on doubling, and no surrender. A commonly seen “good” six-deck game — dealer stands on soft 17, double after split allowed, 3:2 payout — has a house edge of about 0.4–0.5% for a player using perfect basic strategy.
How well you play
Unlike slots or roulette, your decisions change the odds. Every published house-edge figure assumes basic strategy — the mathematically correct play for every combination of your hand and the dealer’s upcard. Playing on instinct instead can easily add 1–2 percentage points to the edge, wiping out the advantage a good table gives you. Learning the chart is the single most valuable thing a player can do; start with our blackjack strategy guide.
How blackjack compares to slots and other games
Blackjack’s edge only looks impressive next to the rest of the casino floor. Slot machines, the most popular casino product in Canada, typically run a house edge anywhere from about 2% to 15% depending on the machine and venue — online slots often sit at the friendlier end (RTP above 96%), while land-based machines can be far tighter. The table below puts common games side by side, using standard rule sets and correct play where skill is involved.
Comparison
| Game | Typical house edge | Approx. RTP |
|---|---|---|
| Blackjack — 3:2, basic strategy | ~0.4–0.5% | ~99.5% |
| Blackjack — 6:5, basic strategy | ~1.5–2% | ~98–98.5% |
| Baccarat — banker bet | ~1.06% | ~98.9% |
| European roulette (single zero) | 2.70% | 97.3% |
| American roulette (double zero) | 5.26% | 94.74% |
| Slot machines | ~2–15% | ~85–98% |
The takeaway is not that blackjack is a way to make money — it is not. It is that, played correctly, blackjack lets a Canadian player keep more of their bankroll in play for longer than almost any other game. For a broader look at the legal and practical side of playing here, see our overview of blackjack in Canada.
Go deeper into the numbers
This pillar is the map; the detailed maths lives in the guides below (some are still being published in this section):
- House edge in detail — how each rule shifts the percentage, with worked examples for common Canadian table configurations.
- 3:2 vs 6:5 payouts — exactly how much a 6:5 table costs you per hour, and how to spot one.
- Odds and probability — the full breakdown of dealt hands, dealer outcomes and long-run expectation.
You can always return to the blackjack guide home page to browse every section.
Common misunderstandings about blackjack odds
- “I’m due for a win.” Each hand is independent; past results do not change the next deal’s probabilities.
- “A betting system beats the house edge.” No progression — Martingale or otherwise — changes the underlying odds. It only reshapes how wins and losses are distributed, usually toward a bigger risk of ruin.
- “Insurance protects me.” The insurance side bet carries a large house edge of its own and is a losing proposition for the vast majority of players.
- “RTP means I’ll get 99.5% back tonight.” RTP is a long-run average across enormous samples, not a refund rate for a single session.
Responsible gambling
Blackjack is a form of gambling with a built-in mathematical advantage for the operator. Even at the best table, the expected long-run result for the player is a loss, and no strategy on this site can change that. The information here is educational and is not a promise of winnings or financial advice. Set a budget you can afford to lose, treat any money spent as the cost of entertainment, and never chase losses.
Gambling services and self-exclusion tools in Canada are legal only for adults (18 or 19, depending on your province or territory). If gambling stops feeling like fun, free and confidential help is available across Canada. In Ontario, ConnexOntario offers 24/7 support at 1-866-531-2600; the Responsible Gambling Council provides help lines and resources for every province and territory. Our responsible gambling page lists the tools and contacts in one place.
Sources
Frequently Asked Questions (FAQ)
What is the house edge in blackjack?
Played with correct basic strategy at a good table — six decks, dealer stands on soft 17, 3:2 payout — the house edge is roughly 0.4% to 0.5%, meaning the casino expects to keep about 40 to 50 cents of every $100 wagered over the long run. Poorer rules or careless play push that figure much higher.
What is the difference between house edge and RTP?
They describe the same thing from opposite sides. House edge is the share of your bets the casino keeps on average; RTP (return to player) is the share it pays back. They always add up to 100%, so a 0.5% house edge equals a 99.5% RTP.
Why is a 6:5 blackjack table worse than a 3:2 table?
At 3:2, a natural blackjack on a $10 bet pays $15; at 6:5 it pays only $12. That reduced payout adds roughly 1.3 to 1.4 percentage points to the house edge — often tripling the cost of the game — even when every other rule is identical.
What are the odds of winning a hand of blackjack?
Using basic strategy, you win about 42% of hands, push (tie) about 9%, and lose about 49%. Ignoring pushes, your chance of winning a resolved hand is around 46%. You win slightly less often than you lose, and that small gap is the house edge.
How does blackjack compare to slot machines?
Blackjack played correctly has one of the lowest house edges in the casino, around 0.5%. Slot machines typically run a house edge of about 2% to 15% depending on the machine and venue, so a bankroll generally lasts far longer at a well-chosen blackjack table.