Here's the Approximate quote API request and response that we are going to use to calculate the exchange rate for the sake of demonstration. In this example, the end-user wants to buy 200 USD worth of USDT, all fees are included in the requested amount of 200 USD:

curl --location 'https://app-api.sandbox.coinify.com/partners/24d17a54-81e6-464b-aba8-30935fc0fd3f/approximate-quote?transferInMedium=card&transferOutMedium=blockchain&quoteCurrency=USDT&sendAmount=-200&sendCurrency=USD' \
--header 'Authorization: Bearer eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.eyJpYXQiOjE3MzEzMjk0OTIsImV4cCI6MTczMTMzMDY5MiwidWlkIjo1ODYxNywiZXYiOnRydWUsInNjIjp7InRfMTM0NTAiOiIqIn19.mMGg9mdzSqwayb6rPhNNgp36HmEvesASkgtMxSOfgt6CX5-RwuCk_TEl4p5SMGPmiVrNhmmTcjHMugoAEdFQQw' \
--data ''

{
    "baseAmount": -177.28,//sendAmount - transferIn.feeAmount
    "baseCurrency": "USD",
    "sendAmount": -200,
    "sendCurrency": "USD",
    "quoteAmount": 177.1223611,//the quoted amount. Shows how much cryptocurrency X will the customer get for the baseAmount
    "quoteCurrency": "USDT",
    "receiveAmount": 175.93502096,//the amount end-user will receive after network transaction fees (transferOut.feeAmount) deducted
    "receiveCurrency": "USDT",
    "transferIn": {
        "medium": "card",
        "feeAmount": 22.71,
        "currency": "USD"
    },
    "transferOut": {
        "medium": "blockchain",
        "feeAmount": 1.18734014,//network transaction fees
        "currency": "USDT"
    }
}

Exchange Rate Calculation

baseAmount / quoteAmount = 177.28 / 177.12 = 1.00090334