Betting odds tell you two things at once: how likely a sportsbook thinks an
outcome is, and how much a winning wager will pay out. Alberta sportsbooks
commonly display odds in one of three formats – decimal, American or fractional –
and switching between them is mostly a matter of familiarity rather than any one
format being “better.”
This guide breaks down each format with worked examples, explains implied
probability and bookmaker margin, and shows how to compare prices across
sportsbooks before placing a bet.
How Decimal Odds Work
Decimal odds are the most common format shown by Canadian sportsbooks. The number
represents the total return for every $1 staked, including your original stake.
At decimal odds of 2.50, a $20 stake returns $50 total if the
bet wins – your original $20 plus $30 in winnings. At odds of 1.80,
the same $20 stake would return $36 total.
How American Odds Work
American odds use a positive or negative number relative to a $100 reference stake.
A negative number shows how much you need to stake to win $100; a positive number
shows how much a $100 stake would win.
Odds of -150 mean a $150 stake wins $100 profit (a $250 total
return). Odds of +130 mean a $100 stake wins $130 profit (a
$230 total return).
How Fractional Odds Work
Fractional odds, common in some international markets, express potential profit as
a ratio to your stake. Odds of 5/1 mean a $10 stake profits $50 (a
$60 total return). Odds of 4/5 mean a $10 stake profits $8 (an $18
total return).
The Same Price in Three Formats
| Decimal | American | Fractional | $10 Stake Returns |
|---|---|---|---|
| 1.50 | -200 | 1/2 | $15.00 |
| 2.00 | +100 | 1/1 | $20.00 |
| 3.00 | +200 | 2/1 | $30.00 |
These three rows describe identical prices – only the presentation changes.
Recognizing this makes it easier to compare a sportsbook’s odds regardless of
which format it displays by default.
Implied Probability and Bookmaker Margin
Odds also imply a probability. Decimal odds of 2.00 imply roughly a 50% chance of
that outcome, calculated as 1 divided by the decimal odds. However, sportsbooks
build in a margin – sometimes called the “vig” or “juice” – so the implied
probabilities on all outcomes in a market typically add up to slightly more than
100%. That difference is the bookmaker’s built-in edge, and it is one reason
comparing prices across sportsbooks can matter for value over the long run.
A two-outcome market priced at decimal odds of 1.91 on both sides implies a
probability of about 52.4% each (1 ÷ 1.91). Added together, that is roughly
104.8% – the extra 4.8% above 100% is the sportsbook’s overround, built into
the price rather than shown as a separate fee.
outcome. A favourite can still lose, and an underdog priced at long odds can still
win.
Total Return vs. Profit
Odds calculations can describe either the total return (your stake plus winnings)
or the profit alone (winnings only), and mixing the two up is a common source of
confusion. Decimal odds always express total return. American odds and fractional
odds express profit relative to a stake, so your original stake needs to be added
back separately to find the total return.
Total Return
What you receive if the bet wins, including your original stake back –
the figure decimal odds calculate directly.
Profit
What you gain on top of your stake – the figure American and fractional
odds describe before the stake is added back in.
Reading Odds Before You Bet
Shorter Odds
A price closer to even money (decimal 2.00, American +100) suggests the
sportsbook sees the outcome as roughly a coin flip.
Longer Odds
Higher decimal odds or a larger positive American number suggest a less
likely outcome, with a correspondingly larger payout if it happens.
Before confirming a wager, check the odds shown on your betting slip – prices move,
and the number you first saw may not match what you are about to confirm. Our
beginner’s guide to sports betting
covers the full process from choosing a market to settlement.
Why Odds Change Before an Event
Odds are rarely fixed from the moment a market opens until the event starts.
Sportsbooks adjust prices in response to where money is being wagered, team news
such as injuries or lineup changes, and shifts in public opinion about an outcome.
A price you saw in the morning may not be the price shown on your betting slip that
evening.
Steam Moves
A sudden, sharp shift in odds across multiple sportsbooks at once, often
triggered by significant new information or heavy wagering activity.
Gradual Drift
A slower adjustment as an event approaches, reflecting accumulating bets and
incremental changes in perceived probability.
Neither pattern predicts the outcome of the event itself – both simply reflect how
a sportsbook is managing its own risk across the market.
The “opening odds” are the first price a sportsbook posts when a market becomes
available, while the “closing odds” are the final price just before the event
starts. Comparing the two after the fact is one way experienced bettors track
whether their read on a market lined up with where the price ultimately settled.
How Odds Combine in a Parlay
When multiple selections are combined into a parlay, decimal odds multiply
together to produce the combined price. Two selections at decimal odds of 2.00
each combine to 4.00 total (2.00 × 2.00), meaning a $10 stake would return $40 if
both selections win. Every selection in a parlay normally needs to win for the
whole wager to succeed, which is why parlay odds grow quickly but so does the risk
of losing the entire stake on a single incorrect selection.
Odds and Alberta’s Regulated Sportsbooks
Odds and pricing can differ between sportsbooks operating in Alberta’s regulated
iGaming market, so the same event may pay out differently depending on the
platform. Compare prices where practical, and always confirm that the sportsbook
you are using participates in Alberta’s regulated market before wagering.
Betting Odds – Frequently Asked Questions
Which odds format do Canadian sportsbooks use?
Decimal odds are most common, though many
platforms let you switch to American or fractional display in account
settings.
What does a negative American odds number mean?
A negative number shows the stake needed to win
$100 – it identifies the favourite in a market, not a worse price by
definition.
What is bookmaker margin?
It is the built-in edge a sportsbook prices into
a market so that implied probabilities across all outcomes add up to slightly
more than 100%.
Do higher odds mean a better bet?
Higher odds mean a larger payout if the bet
wins, but they also reflect a lower implied probability of that outcome
happening.
Bet Within a Plan
Understanding odds helps you read a price – it does not remove the risk of
losing a wager.
Decide your stakes as part of a wider gambling budget rather than in reaction to an
attractive price. Our
bankroll management guide
covers setting limits that hold up over time.
educational purposes only. Odds and pricing vary between sportsbooks and can change
at any time. No odds format or calculation guarantees a winning outcome. 18+.
