The Roblox marketplace fee is the most consequential number that most sellers never put in their math. It is a flat 30% taken at the moment of sale, before the money reaches your account, on gamepasses, dev products, group payouts, and limited resales. You never see the 30%, which is exactly why it is so easy to forget how much of your revenue it is.
Price a product as if the fee is not there and you are budgeting a business on its gross instead of its take. The gap between those two numbers is large, and it compounds over a month of sales.
What the cut actually costs
A 100 Robux gamepass returns 70 to the seller. A 1,000 Robux dev product nets 700. The fee is not a rounding error you can ignore; it is nearly a third of everything, applied to every transaction, forever. The tax calculator multiplies a price by a unit count and shows the post-fee take, which is the number you should be pricing against, not the sticker.
Group payouts work the same way. A group sitting on 10,000 Robux that pays all of it out leaves the receiving member with 7,000, because the cut applies on the way to a personal balance. The Robux that lands on a member's account is what becomes eligible for cashout, not the original group balance.
Where it stacks with DevEx
Here is the part that turns a tax into a double tax. The 30% comes off first, and then the surviving Robux meets the DevEx rate of $0.0035 each when you cash out.
Run the 100 Robux gamepass all the way through. You keep 70 after the fee. You DevEx that 70 and land about 25 cents. The buyer paid roughly $1.25 in purchased Robux to get the pass. So a dollar-and-a-quarter of spending becomes a quarter of earnings, and the platform took a share at both ends of the same transaction. That is not a complaint, it is just the arithmetic, and it is the arithmetic most "I'll make money on Roblox" plans skip.
Planning around it
You cannot avoid the fee, so the move is to price with it baked in from the start. Decide what post-fee take you want, then work backwards to the sticker price and the volume you would need. The gamepass profit calculator does that projection, multiplying a candidate price by expected monthly sales so you can see the real take before you publish anything.
The other lever is volume math. Dev products and gamepasses pay the same 30%, but they sell differently, and a cheaper item bought often can out-earn a premium one bought rarely. The fee is constant; the strategy is in how many units you can move at a price the post-fee number still rewards.
It hits trades too, not just sales
The fee is easy to think of as a developer problem, but it reaches traders as well. Limited resales on the marketplace carry the same kind of cut, so flipping items for Robux is not the clean arbitrage it looks like once the marketplace takes its share of each sale. Any plan that involves buying low and selling high through the catalog has to clear the fee on the way out, and a margin that looked healthy at the sticker can vanish at the take.
The monthly version makes it vivid. A gamepass at 199 Robux selling 250 times a month grosses 49,750 Robux. The fee takes 14,925 of it. Your take is 34,825, about $122 in DevEx terms before tax. To clear $500 a month from that pass you would need to roughly quadruple sales or raise the price, and knowing that before you launch is the difference between a plan and a wish.
None of this makes Roblox a bad place to sell. It makes it a place with a clearly posted, very large transaction cost, and the developers who do well are the ones who priced for the take instead of the sticker. The 30% is not hidden. It is just easy to forget, right up until you do the math on what actually reached your account.