Most bettors close out a profitable stretch on a prediction market and count every dollar paid out on winning contracts as profit, without subtracting what was spent on losing contracts or the fees the exchange took along the way. The number left over is usually smaller than it looks, and none of it has been set aside for what’s owed on it.
This calculator takes total payouts, total spent, and fees paid and returns net profit for the year. It then applies a chosen federal marginal rate and state rate to that profit, showing an estimated tax bill, what’s left after tax, and the effective rate the profit actually carries.
The first field is total paid out on winning contracts, the gross amount the exchange credited back on trades that resolved in the bettor’s favor. The second field is total spent on contracts, covering both winners and losers, since that’s the full cost of playing. The third field is fees paid, whatever the exchange charged on top of the trades themselves.
After that comes the federal marginal rate, chosen from the standard brackets running from 10% up to 37%, followed by a state rate entered as a percentage. The result shows net profit for the year, an estimated federal tax, an estimated state tax, the amount left after both, and the effective rate that tax represents against the profit.
Net profit for the year is total paid out minus total spent minus fees paid. Feed in $5,000 paid out on winning contracts, $4,200 spent across winners and losers, and $60 in fees, and net profit lands at $740.00, since $5,000 minus $4,200 minus $60 equals that amount.
From there, the federal marginal rate applies to that $740.00, and a 22% rate produces $162.80 in estimated federal tax. A 5% state rate adds $37.00 on top. Total tax comes to $199.80, which leaves $540.20 after tax, and dividing that tax by the $740.00 profit puts the effective rate at 27.0%, higher than either marginal rate alone because both taxes stack on the same number.
This number matters most right after a profitable stretch, before any of that payout gets treated as spendable cash. Prediction market profit is taxable income, and a bettor who spends the full payout total has already spent money that isn’t fully theirs. The common mistake is running the math on gross payouts instead of net profit, or skipping fees because they look small trade by trade.
Another mistake is assuming every loss automatically offsets every gain, which depends on how the platform reports activity and on the bettor’s own situation. A sharp bettor runs the estimate at their actual marginal rate, sets aside the tax portion before it becomes part of next year’s bankroll, and treats the effective rate as a planning number, leaving exact reporting and loss offset rules to a tax professional.
Does this calculator give the exact amount owed? No. It applies the federal and state rates entered to the profit calculated and produces an estimate, not a filed tax figure, since actual liability depends on the rest of a bettor’s income and situation.
How is net profit calculated? Net profit is total paid out on winning contracts minus total spent on contracts, covering both winners and losers, minus fees paid, leaving the amount actually gained for the year.
What happens if net profit comes out negative? The federal and state rates only apply to a positive net, so a losing year on the platform doesn’t generate an estimated tax on this page.
Do losing contracts offset winning ones for tax purposes? That depends on how the specific exchange reports activity and on the bettor’s broader tax situation, which is a question for a tax professional rather than this estimate.