1 Trace the outline of the bucket to be measured on a large piece of cardboard or paper. While interior shape should be accurate, the exterior shape can be included as reference. 
1  Trace Bucket Shape 
2 Define the Cross Section of the load by constructing the heap area on top of the area contained within the bucket.

2  Define Cross Section of Load  Construct "Heap" and add to Inside Load 
3 Draw a grid of horizontal and vertical lines over the whole bucket load. For larger buckets the lines can be on 12" centers yielding squares of 1 square foot each. For smaller buckets, use a smaller grid, perhaps 6" centers to yield 1/4 square foot per square, for more accuracy.  3  Draw a grid over the load area 
4 Sequentially number all the whole squares that cover the load in the bucket ignoring for the moment, any parts of the load that are not covered by whole squares.  4  Count up all the whole squares covering the load 
5 Group bits and pieces of partial squares to add up to whole squares.Count up all the additional squares that are made up of all the small pieces. (Try to be accurate but don't go overboard with this exercise. Where some squares might be a little under filled, others will be over, canceling out error.) In this illustration we have 52 squares so the cross sectional area of this load is 52 square feet.  5  Group partial squares into whole squares 
6 Calculate the
volume by multiplying the cross sectional area
in square feet by the length in feet. Using the
148" width as an example:
148 inches in feet is: 148 / 12 = 12.33 feet In North America, most bucket capacities are expressed in cubic yards so it is important to know that one cubic yard contains: 1 yard = 3 feet so 3 ft. x 3 ft. x 3 ft. = 27 cubic feet 
Volume is: 52 sq. ft. x 12.33 feet = 641.33 cu. ft. Or expressed as Cubic Yards is 641 / 27 = 23.7 Yards^{3} Where this method has only applied the angle of repose in two dimensions, the SAE Standard Formula applies it in three. Therefore experience tells us that the actual rated capacity of this bucket will be closer to: 23 or 23.25 Yd^{3} 6 Calculate Volume 