berm

Assuming the cross section of the berm is roughly a parabola, your cross sectional area will be about 20 square feet, giving you a volume of about 1,480 cubic feet or about 55 cubic yards. Get some extra to account for compaction.

<Assuming the cross section of the berm is roughly a parabola,>

This is correct assumption.

I don't know where CSM Eng got his calculator but it needs new batteries. 74X10X3 = 2220 Cu Ft * 27 = 82 Cu Yds.

Now we need to know what the Berm is for. If I provide Engineering fill ( this is what I sell the county highway Dept for berming roads) it weighs Apx 3,800 # per yard, # 53 Crushed stone ( State Highway will use this as it is more widely available although it wil not last as long ) will weigh about 3,000 # per yard and # 4 Crushed stone ) private contractors like the look ) will go 2,500 # per yard.

Please re-read the first eleven words of my post. Area of a parabola = 2/3 base x height. My conclusion properly followed my stated assumptions. I see very few square berms - or since you are in the business of providing fill perhaps using this to overestimate is SOP for you?

A parabolic final cross-section would be correct. However, it should be noted that this will only represent the final compacted material. For an estimate of the loose fill material needed, you should consider loose materials as being between 75% and 80% compacted, as an estimate. The final placement should likely be between 75% and 95% compacted, use 90 as typical unless otherwise specified. this should allow you to correct compaction in estimating the amount of materials required in construction.