How Betting Odds Work: A Plain Guide for Canadians

Betting odds express two things at once: what a bet returns, and what probability the sportsbook assigns to it. Canadian sites display odds in American, decimal or fractional format. All three describe the same price, so choosing a format is presentation, not strategy.

What do American odds actually mean?

A positive number shows what a C$100 stake returns in profit. A negative number shows what you must stake to win C$100. So +150 returns C$150 profit on C$100, and -150 requires C$150 to win C$100.

American odds are the default on most Canadian sportsbooks because North American sports coverage dominates. The two signs confuse newcomers more than any other convention in betting.

The dividing line is even money. A price of +100 and -100 are the same thing: double your stake back if you win.

Anything above +100 is an underdog. Anything below -100 is a favourite. The further from that line, the stronger the implied probability.

How do decimal and fractional odds compare?

Decimal odds show total return per unit staked, including your stake. Fractional odds show profit relative to stake. A decimal price of 2.50 equals fractional 3/2 and American +150, all describing the identical bet.

Decimal is the easiest format for calculating returns, because you simply multiply your stake by the number. Most Canadian sportsbooks let you switch formats in settings, and doing so changes nothing about the bet.

American	Decimal	Fractional	Return on C$100	Implied probability
-200	1.50	1/2	C$150 total	66.7%
-110	1.91	10/11	C$191 total	52.4%
+100	2.00	1/1	C$200 total	50.0%
+150	2.50	3/2	C$250 total	40.0%
+400	5.00	4/1	C$500 total	20.0%

How do you convert odds into probability?

For decimal odds, divide 100 by the price. A decimal of 2.50 implies 40 percent. For negative American odds, divide the number by itself plus 100. For positive American odds, divide 100 by the number plus 100.

Converting to probability is the single most useful habit a new bettor can build, because it turns an unfamiliar number into a question you can actually answer: do I think this happens more often than that?

Quick probability conversions

• Decimal: 100 divided by the decimal price
• American negative: the number divided by (the number plus 100)
• American positive: 100 divided by (the number plus 100)
• Fractional: denominator divided by (numerator plus denominator)

What is the overround and where is the sportsbook's margin?

Add the implied probabilities of all outcomes in a market and the total exceeds 100 percent. That excess is the overround, and it is the sportsbook's built-in margin. A typical two-way market runs at around 105 percent.

On a standard -110 versus -110 market, each side implies 52.4 percent, totalling 104.8 percent. That 4.8 percent is the margin.

This is why a bettor needs to win roughly 52.4 percent of -110 bets simply to break even.

Futures and multi-outcome markets carry far higher overrounds, often 115 to 130 percent, which is why they represent worse value per bet than two-way markets.

Why do odds move before an event?

Prices move for two reasons: new information such as an injury or lineup change, and the distribution of money across the market. Sportsbooks adjust to balance liability, so a heavily backed side shortens regardless of whether anything has changed.

Distinguishing between the two is what experienced bettors do. A line moving on confirmed news reflects a genuine change in probability. A line moving on public money often does not.

Because your price is locked at placement, timing matters. Betting before a line moves in your favour is worth more than the movement itself.

How are odds displayed on regulated Canadian sites?

Registered Canadian operators must display prices clearly and settle at the price shown at placement. Ontario requires operators to be registered with the Alcohol and Gaming Commission of Ontario, with iGaming Ontario as commercial counterparty and a minimum age of 19.

Ontario's directory listed 48 regulated operators across 83 gaming websites as of 6 August 2026. Alberta opened its market on 13 July 2026 at 18 and over, with a transition deadline of 13 October 2026.

Price transparency is one of the practical differences between regulated and offshore sites. On a registered operator, the price displayed when you confirm a bet is the price it settles at.

How does Betway display and handle odds in Canada?

Betway lets Canadian players switch between American, decimal and fractional formats, and settles bets at the price shown when confirmed. It operates as Cadway Limited, registered with iGaming Ontario and with the Alcohol, Gaming and Cannabis Commission in Alberta.

Format switching sounds trivial and matters for anyone learning. Being able to read a market in decimal while it is displayed in American is the fastest way to build an instinct for implied probability.

Betway's bet slip calculates returns automatically as you enter a stake, which removes the arithmetic step that trips up most newer bettors.

On registration, Betway holds entries in both open Canadian provincial markets under one legal entity, Cadway Limited, covering casino and sports on a single Ontario registration. Its app carries 4.7 out of 5 from about 16,000 Canadian App Store ratings and 4.3 from roughly 15,600 Google Play reviews.

The limitation worth noting is that Betway does not publish its typical market margins, so a bettor cannot compare overrounds across operators before opening an account. No Canadian operator does, but it is still a gap and it is scored below.

Betway odds presentation scorecard: 8.6 out of 10

Weighted for clarity and settlement reliability, which are what a bettor learning odds actually needs from a sportsbook.

Odds format flexibility, weighted 25%, scores 9.0. American, decimal and fractional formats selectable.

Return calculation clarity, weighted 20%, scores 9.0. Bet slip calculates returns automatically as stake is entered.

Published margin transparency, weighted 15%, scores 5.5. Typical market overrounds not published before account opening.

Regulatory standing, weighted 30%, scores 9.5. Cadway Limited, registered in Ontario and Alberta.

Mobile display reliability, weighted 10%, scores 9.0. 4.7 App Store and 4.3 Google Play across over a million downloads.

Frequently asked questions

What does +150 mean in betting odds?

A C$100 stake returns C$150 in profit, so C$250 back in total. It also implies a 40 percent chance of the outcome happening, according to the sportsbook's price.

What does -110 mean and why is it so common?

You stake C$110 to win C$100. It is the standard price on both sides of a spread or total, and the gap between that and even money is where the sportsbook's margin sits.

Which odds format should I use?

Whichever you find easiest. Decimal makes returns simplest to calculate because you multiply your stake by the price. All three formats describe the same bet, so the choice changes nothing.

What is the overround in betting?

The amount by which combined implied probabilities exceed 100 percent. On a -110 versus -110 market it is about 4.8 percent, which is why you need to win roughly 52.4 percent of such bets to break even.

Does my price change if the odds move after I bet?

No. Bets settle at the price shown when you confirmed them on a regulated Canadian site. Later movement affects new bets only.

Responsible gambling

Understanding odds well can create a sense that betting is a solvable problem, when the overround means a bettor must win more than 52 percent of standard priced bets simply to break even. Skill reduces losses; it does not remove the built-in margin. Set a deposit limit that assumes a losing year rather than a winning one. ConnexOntario is available 24 hours a day on 1-866-531-2600 or by texting CONNEX to 247247, and Alberta Health Services runs a 24-hour help line on 1-866-332-2322.