> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tender.cash/llms.txt
> Use this file to discover all available pages before exploring further.

# Calculate Conversion Fee

> Get a fee quote for converting a given coin/chain amount, with optional destination for crypto swaps

<Note>
  **Auth method: Signed (HMAC)** — this endpoint requires the full set of signed
  headers: `x-access-id`, `x-request-id`, `x-timestamp`, and an HMAC-SHA256
  `authorization` signature. See [Authentication](/api-reference/authentication#signed-hmac-authentication).
</Note>

## Headers

<ParamField header="x-access-id" type="string" required>
  Your API access ID provided by Tender

  **Example:** `"your-access-id-here"`
</ParamField>

## Path Parameters

<ParamField path="chain" type="string" required>
  Source chain identifier

  **Example:** `"ethereum"`
</ParamField>

<ParamField path="coin" type="string" required>
  Source coin identifier

  **Example:** `"usdt"`
</ParamField>

<ParamField path="amount" type="string" required>
  Amount to convert

  **Example:** `"100"`
</ParamField>

## Query Parameters

<ParamField query="toChain" type="string">
  Destination chain for a crypto swap quote

  **Example:** `"solana"`
</ParamField>

<ParamField query="toCoin" type="string">
  Destination coin for a crypto swap quote

  **Example:** `"sol"`
</ParamField>

## Response

<ResponseField name="status" type="string" required>
  **Example:** `"success"`
</ResponseField>

<ResponseField name="message" type="string" required>
  **Example:** `"success"`
</ResponseField>

<ResponseField name="data" type="object" required>
  Conversion fee quote

  <Expandable title="data properties">
    <ResponseField name="amount" type="number">
      Source amount

      **Example:** `100`
    </ResponseField>

    <ResponseField name="amountUSD" type="number">
      Source amount in USD

      **Example:** `100.00`
    </ResponseField>

    <ResponseField name="fee" type="number">
      Conversion fee in source coin

      **Example:** `0.5`
    </ResponseField>

    <ResponseField name="feeUSD" type="number">
      Conversion fee in USD

      **Example:** `0.50`
    </ResponseField>

    <ResponseField name="amountAfterFee" type="number">
      Amount you will convert after fees are deducted

      **Example:** `99.5`
    </ResponseField>

    <ResponseField name="estimatedOutput" type="number">
      Estimated destination amount (crypto swaps only)

      **Example:** `1.24`
    </ResponseField>

    <ResponseField name="rate" type="number">
      Exchange rate applied

      **Example:** `0.0125`
    </ResponseField>
  </Expandable>
</ResponseField>