Odds and stake tools, with the arithmetic shown

The tools

Type a number, press the button. Nothing is sent anywhere and nothing is stored.

Odds converter

Turns one price into the other two formats and into an implied probability.

Odds converter inputs

Format you have Decimal, for example 2.50 Fractional, for example 3/2 American, for example +150 Price

Convert

Implied probability is 1 divided by the decimal price.

Stake and return

Shows what a stake returns at a decimal price, before any bonus condition.

Stake and return inputs

Stake in USD Decimal price

Calculate

Total return is stake multiplied by the decimal price. Profit is the return minus the stake.

Margin checker

Add the prices of every outcome in one market to see the operator's built in edge.

Margin checker inputs

Outcome one, decimal price Outcome two, decimal price Outcome three, decimal price, optional

Check the margin

Add 1 divided by each price. Anything above 100 percent is the operator's margin.

These tools describe prices you give them. They do not predict results, do not recommend a stake and do not know whether a bet is a good idea. If either tool disagrees with your operator's own bet slip, the operator's slip is the one that settles.

Reading the results

• Implied probability is 1 divided by the decimal price. A price of 2.00 implies 50 percent, a price of 4.00 implies 25 percent.
• Total return includes your stake. Profit is the return minus the stake, which is the number most people actually mean.
• A margin above zero means the prices in that market add up to more than 100 percent of probability. That surplus is the operator's edge and it applies to every bet in the market.
• Comparing the same market at two operators, using the margin checker on each, is the single most useful thing these tools do.

Worked example

Say a match is priced 2.10 for the home win, 3.40 for the draw and 3.60 for the away win. The implied probabilities are about 47.6, 29.4 and 27.8 percent, which add to roughly 104.8 percent. The 4.8 percentage points above 100 are the operator's margin on that market. A second operator pricing the same match at a total of 102 percent is offering better value on identical outcomes, whatever either of them says about welcome offers.

Margin is the one number that is comparable across every operator on this site, in every country, without needing to trust anybody's rating.

What these tools deliberately do not do

• They do not suggest a stake size. Bankroll rules are not arithmetic, they are personal circumstances.
• They do not model accumulators as a good idea. Multiplying prices also multiplies the margin against you.
• They do not price a bet for you or tell you whether a price is wrong.
• They do not store anything. Reload the page and every field is empty again.

Gambling Therapy offers free, confidential support internationally if betting has stopped being entertainment.

Important. 18 plus only. Understanding a price better does not make betting profitable. The margin is designed so that most people lose over time.

Questions readers ask

Do the tools need an internet connection

Only to load the page. The arithmetic runs in your browser, nothing is sent to a server, and nothing is stored between visits.

Why is there no accumulator calculator

Because the honest output would be discouraging and the tool would mostly be used to make it look attractive. Multiplying four prices multiplies four margins against you, which is the part most accumulator tools quietly omit.

Which odds format should I use

Whichever your operator shows by default. Decimal is easiest for arithmetic, which is why the return and margin tools ask for it.

Can these tools tell me if a price is good

Not on its own. What they can do is show you the margin in a market, which lets you compare the same market at two operators on a like for like basis.