Hi Christian,
Thank you for reaching out to us. You can calculate the cost from micros by taking the micro amount and dividing it by 1,000,000. For example, $1.23 will come back as 1230000 in micros. Micro amounts also reflect the account’s local currency. Therefore, if your account is set to use USD, it should provide the micros in USD x 1,000,000. You can read here for more details. Let me know if you have further questions.
Thank you,
Bryan, Google Ads API Team