Size of Empty UDP and TCP Packet

Size of Empty UDP and TCP Packet :

Size of Ethernet frame - 24 Bytes
Size of IPv4 Header (without any options) - 20 bytes
Size of TCP Header (without any options) - 20 Bytes
So total size of empty TCP datagram - 24 + 20 + 20 = 64 bytes

Size of UDP header - 8 bytes
So total size of empty UDP datagram - 24 + 20 + 8 = 52 bytes

What might be misleading when looking at the structure of an Ethernet frame [see further reading], 
is that without payload the minimum size of an Ethernet frame would be 18 bytes: Dst Mac(6) + Src Mac(6) + Length (2) + Fcs(4), 
adding minimum size of IPv4 (20) and TCP (20) gives us a total of 58 bytes.

What has not been mentioned yet is that the minimum payload of an ethernet frame is 46 byte,
so the 20+20 byte from the IPv4 an TCP are not enough payload! This means that 6 bytes have to be padded, 
thats where the total of 64 bytes is coming from.

18(min. Ethernet "header" fields) + 6(padding) + 20(IPv4) + 20(TCP) = 64 bytes