(i) Percentage of direct labour cost. Here, all overhead costs are apportioned according to direct labour cost by means of a labour burden rate, which is the ratio of the annual total indirect expenses to the annual direct labour cost. It is then assumed that this burden rate also represents the ratio of hourly overhead costs to hourly labour costs. That is
Overhead rate = (Total overheads in Rs.for a period)/(Direct labour in Rs.for a period)
Overhead cost =overhead rate ×direct labour cost per unit per unit