If you have meaningful trading gains and little withholding, the IRS expects you to pay estimated tax four times a year, not just in April. Skip it and you can owe an underpayment penalty even if you pay in full at filing. This calculator gives you a quick, directional estimate of what to set aside each quarter.
Enter your expected net gain for the year and your rates, pick whether the gains are treated as Section 1256 contracts (60% long-term, 40% short-term) or as ordinary income, and add a state rate if your state taxes the income. The result splits the annual tax into four payments and lists the due dates.
Tax treatment
Per quarter
$0.00
Total est. tax
$0.00
Federal
$0.00
State
$0.00
Effective rate
0%
on the gain
Federal due dates are roughly Apr 15, Jun 15, Sep 15, and Jan 15. This splits your full-year estimate evenly; if your gains are lumpy, size each payment to when you realized the income. Many traders instead pay the safe harbor (90% of this year, or 100–110% of last year) to avoid the underpayment penalty. Educational estimate, not tax advice.
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The federal system is pay-as-you-go. For each quarter you are generally expected to have paid in enough through withholding and estimates to cover that period's income. Trading gains usually have no withholding, so the estimates fall on you.
A common shortcut is the safe harbor: if you pay at least 90% of this year's tax, or 100% of last year's (110% if your prior-year income was high), you avoid the penalty even if you owe more at filing. Many traders base their estimates on the safe harbor rather than guessing this year's total.
Section 1256 and the quarters
If your contracts are Section 1256 contracts, gains are split 60% long-term and 40% short-term regardless of how long you held, which usually lowers the blended rate versus fully ordinary treatment. This calculator applies your long-term rate to 60% and your ordinary rate to 40% when you choose 1256.
The four federal due dates are roughly April 15, June 15, September 15, and January 15 of the following year. They are not evenly spaced on the calendar, so if your gains are lumpy you may want to size each payment to when you actually realized the income rather than splitting evenly.
FAQ
Do I have to pay quarterly taxes on Kalshi gains?
If you expect to owe roughly $1,000 or more at filing and do not have enough withholding to cover it, the IRS generally expects quarterly estimated payments. Otherwise you can face an underpayment penalty even when you pay the full balance in April.
How is the quarterly amount calculated?
This tool estimates your full-year tax on the gain, using either Section 1256's 60/40 split or ordinary treatment plus any state rate, then divides by four. You can also base payments on the safe harbor instead, which many traders prefer.
Is this tax advice?
No. It is an educational estimate to help you plan and set money aside. Your actual liability depends on your full return, and the safe-harbor rules have details this does not model. Confirm with a tax professional.
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ContractTax does this across your whole Kalshi history: real P&L, a Sharp Score that rates your edge, and your tax numbers under every treatment.
These tools are for education and estimation only, not financial or tax advice. Fee estimates use Kalshi’s standard formula and may differ from your actual fees.
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