Every transaction has 10 bytes of required information.
Each output adds another 34 bytes
Each input adds 148 bytes if it was previously received at a compressed key address and 180 bytes if it was received at an uncompressed key address.
Looking at your other post...
This transaction is the one you said you created:
3b16f704f1086d2f3bcfe1716618027045092ab52fec85013ebc2999d50d9174
It has only 1 input of 0.01 bitcoins that were previously received at address 1xExA3dry8eavsAMrtAzZd1KWMk78BiHB (a compressed key address) at 2017-02-23 03:40:00 UTC in transaction b54c0dd3b91bf0137b2d7900d4a0216d9b193bea5125d59188ae6364bd3dca78.
It has only 1 output of 0.00981107 bitcoins sent to address 13Q3jM8fwznuV5WGCRJSwTGFzdjVYE8NnN
The remaining 0.00018893 bitcoins is the transaction fee.
The size of your transaction is:
10 bytes + 34 bytes (one output) + 148 bytes (one compressed key input) = 192 bytes.
The fee you paid is:
0.00018893 bitcoins / 192bytes = 0.00000098 bitcoins per byte
This is one of your friend's transaction:
4126ada7e11d40ea8ba77743571d2ae5562ab41033cce7e253b7e255405a96ea
It has only 1 input of 0.20833 bitcoins that were previously received at address 13Q3jM8fwznuV5WGCRJSwTGFzdjVYE8NnN (an uncompressed key address) at 2017-02-15 15:37:51 UTC in transaction 0fcf2b850d898a55d9264d43c06b8d2c3ab4d6269e97d66cf616deb539dcdcab.
It has 2 outputs
- One output is 0.2 bitcoins sent to 1JmnkuZNXm72v1h2yRY11uNd2UcR27x7LH
- The other output is 0.0081831 bitcoins sent back to address 13Q3jM8fwznuV5WGCRJSwTGFzdjVYE8NnN
The size of your friend's transaction is:
10 bytes + 68 bytes (two outputs) + 180 bytes (one uncompressed key input) = 258 bytes.
The fee your friend paid is:
0.00014690 bitcoins / 258 bytes = 0.00000057 bitcoins per byte
Your transaction confirmed faster because you paid a transaction fee that is 0.00000041 bitcoins MORE per byte than your friend.
This is another of your friend's transaction:
1fdaf7e2f50aea9d272165232f578bc62c3875abdd06b2b4bd2e1eb63bf40088
It has only 1 input of 0.06057447 bitcoins that were previously received at address 13Q3jM8fwznuV5WGCRJSwTGFzdjVYE8NnN (an uncompressed key address) at 2017-02-13 08:25:40 UTC in transaction 66f35a46101d441840beef33df0eb1b36bfa61df5f38651235405dae03738387.
It has 2 outputs
- One output is 0.02223 bitcoins sent to 1Aq8nBwVLzXTJvoAt1z11gvbXFMW2i9C7P
- The other output is 0.03818447 bitcoins sent back to address 13Q3jM8fwznuV5WGCRJSwTGFzdjVYE8NnN
The size of your friend's transaction is:
10 bytes + 68 bytes (two outputs) + 180 bytes (one uncompressed key input) = 258 bytes.
The fee your friend paid is:
0.00016 bitcoins / 258 bytes = 0.00000062 bitcoins per byte
Your transaction confirmed faster because you paid a transaction fee that is 0.00000036 bitcoins MORE per byte than your friend.