How to calculate cord volume from log size?

How do you figure the volume of these logs?

2 pieces cherry. The larger is 6’ 6” to the crotch. 20” wide at the base. The other is 5’ and 13” wide

 

If I did it right, I get 14.18 cu ft for first one, 4.61 cu ft for second one, total of 18.79 cu ft.

I use an app called Timberlog. I assume that it is assuming that the log has no taper and it seems unlikely that it would not have a little, so, the numbers are likely slightly high is my thinking.

 

This passes the eyeball test - the 13” log will have darn close to a cubic foot of volume per foot of length (same taper assumption). If both logs were the same it would be 11.5 cu ft. But one is larger, and then there is the air between splits.

 

Thanks for the math and the resource, I'll check that out

 

Firewood & Cord Calcuations

Scroll down to the second calculator. Just enter dimensions.

 

Awesome thanks

 

So roughly 1/4 cord if I'm correct

 

Actually I guess .15 cords

 

I use this guide for standing trees. Pretty accurate.
Estimating Firewood from Standing Trees - UC ANR