Abstract: A construction site offset adapter assembly includes a main body and an end cap. The main body includes a securing device and a measurement pointer. The securing device couples the main body to a level and a measurement device. The measurement pointer is aligned with the lower edge of the level when the main body is coupled to the level. The end cap includes a second securing device and an offset measurement point. The second securing device couples the end cap to the level, and to an offset rod. The offset measurement point is aligned with the lower edge of the level when the end cap is coupled to the level. The construction site offset adapter assembly may include a plurality of securing devices and/or a plurality of second securing devices. The main body may include a plurality of measurement pointers.