The Ethereum fees do not depend on the amount. The main factor influencing the size of the commission is the price for Gas.

Gas is needed for operations to be carried out in the Ethereum Virtual Machine (blocks to be collected, operations to be executed in a smart contract, etc.). 

Each transaction in the Ethereum Virtual machine costs a certain amount of Gas. A transfer costs 21 0000 units of gas. Gas price is measured in ETH, or, more precisely, in its billionth (Gwei).  

1 ETH = 1 000 000 000 Gwei (One billionth). 

The Gas price changes depending on the demand in the system. 

Transaction fee = (Gas price * 21 000)/1 000 000 000. This will be the price in ETH. The price in USD can be calculated based on the current exchange rate.