bitcoin-util-fee/doc/p2pkhspec.txt

utility of bitcoin transaction size calculate

PREVOUT: hash (32 bytes)
         index (4 bytes)
SCRIPTSIG: length (1 byte)
           CONTENTS: push opcode (1 byte)
                     signature (72 bytes)
                     push opcode (1 byte)
                     pubkey (33 bytes for compressed, 65 for uncompressed)
sequence (4 bytes)

= 148