Refinery processing size or capacity usually is measured in terms of crude distillation unit capacity. Common units for refinery capacity measurement are:
BCD – Barrels per Calendar Day, based on 360 days per year, allowing downtime for maintenance, and
BSD – Barrels per Stream Day, i.e. the nameplate or maximum capacity of the refinery.
For refinery operation, the capacity in terms of m3 per hour is used e.g. if the capacity of the oil refinery is 100 K (100000) BPSD then per hour flow is taken 662 m3 (15888 m3/day).