About RBXKit
An independent project building fast, accurate calculators for the people who create on Roblox.
Why RBXKit exists
Creators shouldn't have to do fee math in their heads or trust a random spreadsheet. RBXKit puts the two calculations creators reach for most (the marketplace fee and DevEx cash-out) behind a fast, honest interface with the formulas shown in the open.
Who's behind it
StarkRBLX
Roblox & web developer. Five-plus years building Roblox experiences in Lua alongside modern web apps in Next.js and React. RBXKit grew out of wanting the fee and DevEx math to be as reliable as the rest of the toolchain.
starkrblx.com →RBXKit is independently built and maintained by StarkRBLX. It is not affiliated with, endorsed by, or sponsored by Roblox Corporation.
How the tools are maintained
Fee and rate figures live in a single configuration file and are reviewed against Roblox's published sources. When Roblox changes a rate, we update that file and note the date on the affected pages. Our approach to accuracy and corrections is described in the editorial policy.
Get in touch
Spotted an error or have a calculator you'd like to see? The contact page has the details, or reach out directly via Discord through starkrblx.com.