Odds and stake tools, with the arithmetic shown
Three small tools that do arithmetic on numbers you type in. Each one shows the formula it used, so you can check it by hand and stop needing the tool.
No live prices, no predictions, no staking advice. Arithmetic only.
- Formula shown
- Works offline once loaded
- 18 plus only
The tools
Type a number, press the button. Nothing is sent anywhere and nothing is stored.
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.
- Run the margin checker on the same market at two operators. A market totalling 102% against one totalling 106% is 4 percentage points of your money, on identical outcomes.
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 comparable across all 19 operators on this site, in every country, without trusting anybody's rating.
Where the arithmetic stops
- Stake size is not arithmetic. What you can afford to lose is a fact about your circumstances, so no tool here suggests a number.
- Accumulators, covered in the football guide, multiply the margin as well as the price. Four legs from markets at 4.8% each leave about 83% of fair value, which is why there is no accumulator tool here.
- A price being high does not make it wrong. These tools describe the price you type in, and none of them knows anything about the match.
- Nothing is stored. The arithmetic runs in your browser and reloading the page clears every field.
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 multiplying four prices multiplies four margins against you. Four legs at 4.8% compound to about 17% against you, which is the part most accumulator tools quietly leave out.
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.