A method performed by a wireless transmitter determining a transport block size (TBS) is provided. The method includes determining a TBS using a general function of a number of physical resource blocks (PRBs) to be granted (N_PRB), a number of resource elements (REs) per PRB (N_RE{circumflex over ( )}(DL,PRB)), a number of layers per transport block (ν), a number of bits per modulation (Q_m), and a coding rate determined by a modulation coding scheme (MCS) (R), allocating a transport block of the determined TBS and transmitting the transport block to a wireless receiver. Apparatuses for implementing the method are also provide.