How to measure a log

[buzz]

Hello all ,    would like to know how measure a log , searched archives had no luck , thanks in advance

[beenthere]

Unless I am missing the point, try the calculators to the left of these messages. Go into log volume, and enter the diam. sm. end, and the length. Get three measures of board footage estimated in your log.

Or is it more in depth than that QA?

[Ron Scott]

Use the calculator at the tool box to the left. Decide what log scale you want to use, Doyle, Scribner, Scribner Decimal C, or International 1/4.

Measure the log's length and diameter "inside bark" at the small end for gross scale. Deduct for any cull, defects, sweep etc for net scale.

The Forum Calculator does the work for you or use one of the appropriate scale sticks which may have the calculations on it.

[Ron Wenrich]

The only thing I would add is that sometimes your log isn't perfectly round.  You can either measure the wide way and the narrow way and average the two, or you can measure across the diagonal.  That will give you a pretty good diameter measurement.

[buzz]

I think what i meant to say was what is the formula ,length x width x ?  should have been more specific , thanks

[beenthere]

There are many different log rules - some with formulas and some where the boards were just drawn in the 'log' on paper to figure out the volume in board feet. If you want to know a lot about the different rules, there is a pretty good publication "A Collection of Log Rules" by Frank Freese

http://www.fpl.fs.fed.us/documnts/FPLGTR/fplgtr01.pdf

that would be good to read. Otherwise, could you be more specific about what it is you want beyond using the calculators on this site, where the scaling diameter and log length are provided, and the log volume in board feet from three 'log rules' are given. Apparently that calulator isn't meeting your needs.

[SwampDonkey]

@ Buzz

newton's formula for cubic feet

V=h (A_b + 4A_m + A_u)
        6

h = height
A_b = cross sectional area at base
A_m = cross sectional area at middle
A_u = cross sectional area at top

or for board footage

Doyle Rule for 16 foot logs
V=(D-4)²

D= diameter inside the bark

International Log Rule for 16 foot logs (more accurate)
V=0.88D² - 1.52D - 1.36

Taken from  Forest Mensuration, Husch, Miller and Beers

Individual tree volumes are site and species specific.In New Brunswick we use standard volume tables based on site index. These can be localized by measuring just tree dbh on your site and using regression to plot the resulting curve for a range of DBH.