Work out what a slip returns before you place it, in any coin

The arithmetic behind a single and a multiple

A decimal price already includes the stake, so a single needs one multiplication: return equals stake times odds, and profit is the return minus the stake. A stake of 30 USDT at 2.40 returns 72 USDT, of which 42 is profit.

A multiple multiplies the legs before it touches the stake. The combined price is the first leg's odds times the second's, times the third's, through to the last; the return is the stake times that product. The implied probability of the slip is 1 divided by the combined price. It says how often the sportsbook's own numbers expect the slip to land, margin included, and on a long accumulator it is a sobering figure.

Fractional and American prices pass through decimal on the way in:

Worked example: a 20 USDT treble

The prices here are an example, not quotes from any site: three football legs at 1.90, 2.10 and 1.80, with 20 USDT staked. It is the slip the odds calculator opens with, so the figures below are the ones on your screen.

• Combined odds: 1.90 × 2.10 × 1.80 = 7.182
• Return if all three win: 20 × 7.182 = 143.64 USDT
• Profit: 143.64 − 20 = 123.64 USDT
• Implied probability: 1 ÷ 7.182 = 13.92 per cent

Type 1 into the fee box and the result below the return reads 142.64 USDT, the amount that arrives after a 1 USDT network fee on the way out. The fee belongs to the transfer, not to the bet, so it is the same whether the slip paid 143 USDT or ten times that. On a small slip it is a real share of the profit; on a large one it hardly registers.

The 13.92 per cent line deserves a second look. Each leg on its own was close to an even chance or better. Together they come in about once in seven attempts at the prices offered, and the margin inside each leg is multiplied into the treble along with the odds.

Staking in BTC or USDT: what the coin changes

The coin never changes the odds. It changes what the result means once it leaves the sportsbook.

With a dollar stablecoin the return is close to a fixed sum of money. Tether states that each USDT is pegged 1-to-1 to the US dollar, so 143.64 USDT is about 143.64 dollars on the day you withdraw, and if you count in pounds or rupees only the dollar rate moves. The same reasoning applies to USDC, the other dollar stablecoin at sportsbook cashiers; the page on USDC betting sites lists the cashiers that accept it.

With bitcoin, the slip pays a fixed number of coins and the coin keeps its own price. Put 0.002 BTC on the same treble and the calculator returns 0.014364 BTC. Enter 60,000 as an example value of one bitcoin in your currency and that return is worth 861.84; if bitcoin is lower by the time the withdrawal confirms, the same 0.014364 BTC buys less. The bitcoin project itself warns that the price can rise or fall sharply over short periods, so a winning bitcoin slip is really two positions held together: the bet and the coin. For BTC cashiers and how long each takes to pay, see the bitcoin betting sites comparison.

Fees behave differently on each network. On bitcoin, a transaction that pays less than the fee the network is prioritising at that moment can wait considerably longer for its first confirmation, so the fee chosen on a deposit also decides how soon the stake is credited. A withdrawal fee typed into the calculator turns the printed return into the received one, which is the figure worth comparing between two sportsbooks.

Mistakes the odds calculator cannot catch

The tool does what the prices say. Several things on a real slip change those prices after you place it, and they live in each operator's sports rules rather than on the betting board.

• A void leg. When one selection in a multiple is voided, for instance by a postponed match, sports rules usually remove that leg and settle the slip on the rest. A treble at 7.182 with the 2.10 leg voided becomes a double at 1.90 × 1.80 = 3.42. Drop the legs to two to see the new return.
• A push or a half-win. Asian handicap and totals lines can hand back the stake on a leg, or half of it. On a multiple that leg counts as 1.00, or at a part price for half outcomes, as the rules set out.
• A dead heat. In golf, racing and some player markets, a tie for a paying place cuts the stake or the price on that selection, so the full return shown here is too high.
• Mixing formats. A fractional 5/2 is read correctly in any mode because of the slash, but an American 150 typed without its sign in decimal mode is read as odds of 150. Set the format before typing.
• Profit mistaken for return. Some slips print the potential win as profit, others as the return including the stake. Compare like with like.

Where the price on the slip comes from

Every price the tool multiplies already carries the sportsbook's margin. On a single that is a few per cent; across six legs it compounds into a large slice of the stake. To see how much margin a market holds, the implied probability calculator totals the prices, and the odds converter handles formats.

Prices also differ from one book to the next on the same event. Each crypto sportsbook sets its own lines, and on markets such as crypto basketball betting the handicap or total can sit half a point apart between two sites, which the calculator then turns into a different return. The home page comparison of the best crypto betting sites reads each operator on what happens to that return after settlement: how long the payout takes, how much can leave in a week and when an ID check applies.

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