Methods, systems, and devices for wireless communication are described. Some wireless communications systems may support communication between a user equipment (UE) and a base station on multiple carriers (i.e., carrier aggregation). In some cases, the UE may be scheduled to transmit uplink signals on the different component carriers during transmission time intervals (TTIs) that have different durations. In such cases, it may be appropriate for the UE to determine a maximum transmit power limit relating to the amount of power used for the uplink transmissions on the multiple carriers. As described herein, the UE may identify one of the component carriers as a reference component carrier, and the UE may determine the maximum transmit power limit for a duration of a TTI associated with the reference component carrier. The UE may then transmit on the multiple carriers in compliance with the maximum transmit power limit.