ChamTax is an online calculator that shows the after-tax take-home amount for US Powerball and Mega Millions lottery winnings, for 51 countries of residence. This page breaks down how the tax generally works — a flat 30% US withholding, then whatever your home country adds on top — using Korea's specific rules as a fully worked example. You can calculate your own take-home amount for any supported country right below.
Last updated: 2026-08-03
30-second summary
The tax structure is exactly the same as Powerball - both are ultimately lotteries run by state governments, so US tax law treats them the same way. Non-US residents are classified as nonresident aliens, so 30% federal tax is withheld regardless of which of the 51 supported countries you live in, and most countries also have their own separate reporting requirement.
What's different is the gameplay and the odds. The April 2025 Mega Millions overhaul raised the ticket price from $2 to $5 and cut the Gold Mega Ball pool from 25 to 24 numbers, slightly improving the jackpot odds (to 1 in 290,472,336). In exchange, the prize structure got bigger and the lower-tier payouts increased too.
What happens after the US withholding depends entirely on your own country's tax treaty and domestic law — use the calculator above to see your country's structure. Korea is a good worked example because its case is well-documented, though still a gray area under Korean law specifically: there's no clear official ruling on whether it's taxed like a domestic lottery win - a flat 22-33% separate tax - or whether it has to be added to comprehensive income tax (up to 45%). The tax paid in the US can partly offset this through the foreign tax credit, but how much can vary by case.
Like Powerball, the announced Mega Millions jackpot is based on the annuity option. Choosing the lump sum gets you only about 45-60% of the announced amount in present value. You usually have to decide within 60 days of claiming, and the choice is final once made.
Curious how much you'd actually take home if you won?
Calculate it now →They're sold at the same convenience stores and gas stations as Powerball - in fact most stores sell both games. Services based in Korea that offer to buy tickets online on your behalf may run afoul of Korean law (brokering lottery ticket sales is a criminal offense there), so we don't recommend using them.
Every Tuesday and Friday (Powerball draws Mon/Wed/Sat). You can check past winning numbers on the official site (megamillions.com).
It varies by state, but it's usually 90 days to a year. If you miss the deadline, the prize is forfeited and reverts to the state government.
This page is for informational purposes only and does not sell, resell, or broker lottery tickets. Consult a tax professional for your actual tax filing.