How do I calculate the miners fee for my transaction using BitGo.com API? BitGo.com gives you the options of 'high priority', 'medium priority', 'low priority' and 'very low priority' for setting miners fee when sending bitcoin with their web wallet.

I am using their API to send bitcoins to different addresses. How do I calculate the miners fee (corresponding to any of the various priorities) to pass to the API when sending bitcoins.

Simply put, if I want to send 0.01BTC to an address with medium priority, how do I calculate the miners fee for medium priority (and the others) with their API or any other API.
You can get up-to-date Bitcoin transaction fees from bitcoinfees.21.co.

They also have an API.

If you are a coder, you can use the API to provide a dropdown list allowing your members/users to select the priority they want to use when making a transaction.