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Prediction market payout calculator
A prediction market price is the market's chance, in cents. A share at 40¢ reads as a 40% chance and pays $1.00 if its outcome happens, so every $1 you put in returns $2.50: a payout multiplier of x2.50, which is simply 1 ÷ price.
Calculator
From 2 to 99.
What you put in, in dollars.
If this outcome happens
$25.00x2.50
Pays out
- Implied chance
- 40%
- Payout multiplier
- x2.50
- Shares
- 25
- Net return
- +$15.00
If any other outcome happens, these shares settle at $0.
Spot estimate at this price. A larger order moves the price as it fills; on GADUIN the ticket shows your exact average price and payout before you confirm.
The formula
Everything follows from one fact: a share pays $1.00 if its outcome happens. So shares = amount ÷ price, payout = shares × $1.00, payout multiplier = 1 ÷ price, and implied chance = price ÷ $1.00. The multiplier and the payout are rounded down to the cent, so the figure shown is never more than the price delivers.
Worked examples
What $10.00 returns at common prices, if the outcome happens:
| Price | Implied chance | Payout multiplier | $10.00 pays out | Net return |
|---|---|---|---|---|
| 10¢ | 10% | x10.00 | $100.00 | +$90.00 |
| 25¢ | 25% | x4.00 | $40.00 | +$30.00 |
| 40¢ | 40% | x2.50 | $25.00 | +$15.00 |
| 50¢ | 50% | x2.00 | $20.00 | +$10.00 |
| 62¢ | 62% | x1.61 | $16.12 | +$6.12 |
| 75¢ | 75% | x1.33 | $13.33 | +$3.33 |
| 81¢ | 81% | x1.23 | $12.34 | +$2.34 |
| 90¢ | 90% | x1.11 | $11.11 | +$1.11 |
Price = chance
A price in cents reads straight across as a percentage: 40¢ is a 40% chance, 81¢ an 81% chance. It is the market's view, set by trading, not a promise about what will happen.
The payout multiplier
The multiplier tells you how many times your amount comes back if the outcome happens. It is 1 ÷ price: 50¢ pays out x2.00, 25¢ pays out x4.00 and 81¢ pays out x1.23. Cheaper outcomes pay out more because the market thinks they are less likely.
Buying Yes or No
In a two-outcome market, one Yes share and one No share together always pay exactly $1.00, so their prices add up to about $1.00. If Yes trades at 70¢, No is about 30¢. Buying No at 30¢ is the view that Yes falls short, with a payout multiplier of x3.33.
Three-outcome markets
Flight, train and voyage markets on GADUIN have three outcomes: On time, Delayed and Cancelled. Exactly one of them happens, so their prices add up to 100%. A Cancelled share at 6¢ pays out x16.66 because the market sees a cancellation as unlikely.
Why prices move
Prices move when people trade on new information: a late inbound aircraft, a storm on the route, a signal failure up the line, a queue of ships at anchor. The price you see is the market's view at that moment, and it can change right up to the close.
Price impact: the price you actually get
The calculator uses a single spot price. A real order moves the price as it fills, since each share bought makes the next one a little dearer, so a large order fills at a higher average price than the one on screen. On GADUIN the ticket shows the average price and the exact payout before you confirm.
Selling before the close
You don't have to hold to settlement. While trading is open you can sell your shares at the current price, whether it has risen or fallen since you bought. A sale depends on trading being open and is not guaranteed at any particular price.
Fees
GADUIN charges no trading fee and no settlement fee, so the calculator's payout is the payout: each share of the outcome that happens pays the full $1.00. Other platforms publish their own fee formulas; see how GADUIN compares with other prediction markets.
Payout questions
- How do you calculate a prediction market payout?
- Divide the amount by the price to get shares, then multiply by $1.00. $10 at 40¢ buys 25 shares, which pay $25.00 if the outcome happens: a payout multiplier of x2.50.
- What is implied probability?
- The chance a price implies. Because a share pays $1.00, a price of 62¢ implies about a 62% chance. It is the market's estimate, and it can be wrong.
- Why is the multiplier rounded down?
- So the figure shown never promises more than the price delivers. 1 ÷ 7¢ is 14.2857…, which is shown as x14.28, not x14.29.
- Does the calculator include fees?
- On GADUIN there is nothing to include: no trading or settlement fee. On other platforms, subtract their published fee from the payout.
Put a number on a real flight
Every live market shows its price and what a share pays out. Pick one that's about to close.