# (Legacy) XY Bridge Fee Information

## How is the bridge fee calculated?

Users are able to roughly estimate the cost of a transaction depending on the formulae given below as reference.

* A small portion of fees is taken as a basic commission. Note that one can imagine the ***feeRate*** in the formula below as a constant, or a percentage figure by which any transaction amount (trading volume) should multiply, usually determined by XY DAO.

$$
BridgeFee = Amount \*feeRate
$$

* There are **lower bound** and **upper** **bound** in the Fee Structure to ensure that XY Finance can afford gas fees and will not impose any surcharges upon users. 

$$
\begin{equation}
\left{
\begin{array}{lr}
BridgeFee=minimumFee, & minimumFee > BridgeFee \\
BridgeFee=Amount \cdot feeRate, & minFee < BridgeFee < maximumFee\\
BridgeFee=maximumFee, & BridgeFee > maximumFee \\
\end{array}
\right.
\end{equation}\notag
$$

{% hint style="info" %}
If the trading volume multiplied by ***feeRate*** is less than the ***minimumFee***, then XY Finance will still charge the ***minimumFee*** as a basic commission.

If the trading volume multiplied *by **feeRate*** is more than the ***maximumFee***, then XY Finance will only charge the ***maximumFee*** as a basic commission.
{% endhint %}

{% hint style="info" %}
`feeRate, minimumFee & maximumFee are determined by XY`[`DAO`](https://docs.xy.finance/fee-structure/broken-reference)`.`
{% endhint %}

## How much does the fee cost?

### General Cross-Chain&#x20;

When you perform cross-chain transactions of your assets through mainstream token pools (e.g., USDC/USDT/ETH), the following fees will be charged:

* `feeRate`: 0.050% - 0.400%
* `maximumFee` : $1,000
* `minimumFee`: The following value represent reference minimumFee for different chains; however, it is important to note that the actual prices may be subject to adjustment based on market conditions:
  * `Ethereum`: $15
  * `Avalanche, Cronos, BNB Chain, Optimism, Arbitrum, zkSync Era, Polygon zkEVM, Linea, Base, Mantle, Scroll`: $0.4 - $1.5
  * `Others`: $0.1 - $0.19

### xAsset Bridge&#x20;

The xAsset Bridge helps projects deploy their tokens onto different chains. When you perform cross-chain transactions involving these specific protocol tokens (e.g., XY/NUM), the following fees will be charged:

* `feeRate`: 0.1%
* `maximumFee`:  $1,000
* `minimumFee`: The following values represent the reference minimumFee ranges for different chains. However, it is important to note that actual prices may be subject to adjustment based on market conditions.&#x20;
  * `Ethereum`: $22.5
  * `Avalanche, Cronos, BNB Chain, Optimism, Arbitrum, zkSync Era, Polygon zkEVM, Linea, Base, Mantle`: $0.6 - $1.35
  * `Others`: $0.15 - $0.285

{% hint style="info" %}
Please note that bridge fees are subject to **change based on fluctuations in the market gas price**. If you are interested in integrating our service and **would like to know the current actual price, please feel free to contact us.**
{% endhint %}