> For the complete documentation index, see [llms.txt](https://docs.xpressprotocol.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.xpressprotocol.com/architecture/gas-costs.md).

# Gas costs

Since XPress is a fully on-chain order book exchange, each order placement is associated with a gas fee.

The table below contains the median gas costs of most common operations on XPress on-chain order book, and corresponding dollar equivalent on Sonic.

| Operation           | Gas Units | Gas Cost in $ on Sonic |
| ------------------- | --------- | ---------------------- |
| Market Order (Swap) | 100,000   | \~$0.0001              |
| Place Limit Order   | 200,000   | \~$0.0001              |