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Tennis odds converter

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Type a price, a probability or any kind of odds, and the rest fill in. A prediction market price of 62¢ is the same as a 62% chance, decimal odds of 1.61, fractional odds of about 8/13 and American odds of -163.

What a share costs, from 1 to 99.

The market's chance, in percent.

Return per $1 staked, stake included.

Like 8/13 or 6/4. I show the nearest common fraction.

Like -163 or +150.

At 62¢, a share costs $0.62 and pays $1 if your player wins, so you make 38¢ per share.

How the conversion works

Everything comes from one idea: on a prediction market a winning share pays $1, so the price in dollars is the implied probability. From there:

  • Decimal odds are 1 divided by the price. 62¢ is 1 ÷ 0.62 = 1.61.
  • Fractional odds are the decimal odds minus 1, written as a fraction. 1.61 minus 1 is 0.61, which bookmakers show as 8/13.
  • American odds for a favourite (over 50¢) divide the price by the rest of the dollar and multiply by 100: 0.62 ÷ 0.38 × 100 = 163, shown as -163. For an underdog, divide the rest of the dollar by the price: 0.60 ÷ 0.40 × 100 = 150, shown as +150.

Common conversions

PriceChanceDecimalFractionalAmerican
10¢10%10.009/1+900
20¢20%5.004/1+400
25¢25%4.003/1+300
33¢33%3.032/1+203
40¢40%2.506/4+150
50¢50%2.00Evens+100
60¢60%1.674/6-150
62¢62%1.618/13-163
67¢67%1.491/2-203
75¢75%1.331/3-300
80¢80%1.251/4-400
90¢90%1.111/9-900

Fractional odds are rounded to the nearest fraction bookmakers commonly use, so some are approximate. 33¢ is shown as 2/1, for example, although the exact figure is a touch shorter.

Bookmaker odds include a margin

If you convert a bookmaker's odds for both players and add the two chances together, you'll usually get more than 100%. The extra is the bookmaker's margin. On a busy prediction market the two prices usually add up close to 100%, though you still pay the spread and any trading fee.

Example

A bookmaker offers 1.57 on Player A and 2.35 on Player B. That's 63.7% plus 42.6%, which comes to 106.3%. The extra 6.3% is their margin. On a market, the same match might be 62¢ and 39¢, which adds up to 101%.

What the number doesn't tell you

An implied probability is what the price says, not what will happen. A 62% chance still loses 38% of the time. Use the number to ask whether you think the real chance is higher or lower, as explained in how tennis prices work. For the bigger picture, read tennis trading vs tennis betting.

FAQ

What are decimal odds of 1.61 as a percentage?

About 62%. Divide 1 by the decimal odds: 1 ÷ 1.61 = 0.62.

Why does the fractional answer say "about"?

Bookmakers quote a standard set of fractions like 8/13 and 4/6. I show the closest one, so it can be a small step away from the exact figure.

Are even money odds +100 or -100?

Both mean the same thing: a 50% chance, or decimal odds of 2.00. I show +100.

Does this include fees?

No, it converts the price only. To include costs, use the profit calculator, which has an optional fee field.

Demo only. 77 Tennis uses demo money with no cash value. Nothing here is financial or betting advice. Prices come from Polymarket's public tennis markets, and I'm not affiliated with Polymarket. Prediction markets aren't legal everywhere, so check the rules where you live. If trading stops being fun, stop.

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