Enter a Polymarket price (in cents) or any odds format.
All other fields update live.
Shares and Payout Calculator
For the Polymarket price entered above
Shares purchased
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Profit if it resolves YES
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Total payout if it resolves YES
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Break-even probability
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Common Polymarket Prices
Tap to load a typical contract price.
How Polymarket pricing works
Polymarket runs binary prediction markets where you buy YES or NO
shares in a future event. Each share pays $1 if it resolves in your
favor and $0 if it does not. The market price of a YES share, in
cents, is the market's collective estimate of the probability the
event happens.
The price is the probability
If a YES contract trades at 40 cents, the market is pricing the
event at a 40% chance. The matching NO contract trades near 60
cents (60%). The two sides sum close to 100 cents because of
arbitrage, with small deviations driven by trading fees and the
bid/ask spread. This is much tighter than sportsbook lines, which
typically include a 4 to 8 percent vig.
Converting Polymarket cents to American odds
Treat the cent price as a percentage. Divide 100 by that
percentage to get decimal odds, then convert to American using the
standard rule. At 40 cents the decimal is 100 / 40 = 2.50,
which is American +150. At 80 cents the decimal is
1.25, which is American -400.
The reverse is even simpler. To express a moneyline as a
Polymarket-style price, compute the implied probability and read
that number as cents. American -200 is 66.67% implied,
so the equivalent Polymarket price is about 67 cents.
Shares and payout
A dollar spent at 40 cents buys 2.5 shares. If the event resolves
YES, each share pays out $1, so $100 spent at 40 cents returns
$250: a $150 profit. The same dollars at 80 cents only buy 1.25
shares and return $125 on a $25 profit. The shares calculator
above shows this directly.
Comparing Polymarket to a sportsbook
The reason serious bettors watch prediction markets is that the
no-vig price is sitting right there on screen. Convert a
sportsbook line to implied probability, subtract the vig
proportionally, and compare to the live Polymarket price. If your
book is offering a meaningfully better number on the same outcome,
that is a candidate for a positive expected value bet.
Polymarket Odds Converter FAQ
What does a 40 cent Polymarket price mean?
A price of 40 cents means the market thinks the event has a 40%
chance of resolving YES. Each YES share costs $0.40 and pays $1
if the event happens. In sportsbook terms that is decimal
2.50, American +150, or fractional
3/2.
How do I convert a Polymarket price to American odds?
Read the cent price as a percent. Divide 100 by that number to
get the decimal odds, then apply the decimal-to-American rule. So
25 cents is 25%, decimal 4.00, American
+300. 75 cents is 75%, decimal 1.333,
American -300.
Why don't the YES and NO prices add to exactly 100 cents?
In theory they should, but Polymarket charges a small fee on each
trade and the order book has a bid/ask spread, so the two sides
usually sum to slightly more than 100 cents. The gap is normally
a fraction of a cent on liquid markets, much narrower than a
sportsbook's vig.
Is buying a YES share the same as betting on the event?
Economically yes. You pay the share price up front, and if the
event resolves YES you receive $1 per share. The difference is
that you can sell the share at the current market price at any
time before resolution, which a fixed-odds sportsbook bet does
not allow.
How is Polymarket different from Kalshi?
Polymarket is a decentralized exchange that settles in USDC on
the Polygon network, with markets on essentially any topic. Kalshi
is a CFTC-regulated US derivatives exchange with a narrower set of
event contracts. The pricing math is the same. See the
Kalshi odds
converter for a tool with Kalshi-specific examples.