Methods and apparatus for determining transport block sizes for relaying backhaul subframes from a relay node to a donor base station are described. A transport block size may be adjusted at a relay node by an adjustment factor. The adjustment factor may be based on parameters such as propagation delay between the relay node and donor base station, a multiplexing configuration of control and data information in a relay node subframe, a switching time in a relay node subframe between a downlink and an uplink partition of the subframe, and/or other channel or configuration characteristics.