SawlogCalc 3.2 User’s Manual

v3.2.1 4-02-2017

SawlogCalc is an Android® tool to estimate the weight and lumber yield of a sawlog, using the diameter of the small end of the log, and it's length. The Pro version can also keep lists of logs with running totals, and export the lists via email. Average weights for more than 100 North American tree species are included. You can enter your own species and weights in a custom list. Log rules include Doyle, Scribner Decimal C (formula), Scribner Decimal C (table) and International ¼ inch.

So, your tree is on the ground, bucked to length. How do you use SawlogCalc? Measure the diameter inside the bark, tap the D: button, and tap in the diameter (let's say 25 inches). Hit the =. button to finish the diameter. Enter the length by tapping the L: button and the length (8 feet), again finishing with =. Now tap the species button. If the species of tree you would like isn't shown, select FULL LIST. Scroll through the species list to find the correct one, tap it (check mark it) if you want it to appear in the short list from now on, and then long-press it. For our example, long-press "Ash, white". The Sawlog screen will now show white ash. At the top of the screen, the weight estimate shows 1700 pounds and the lumber yield is 221 board feet (Doyle log rule).

If you are keeping a tally, tap the T+ button to add the log to the active tally. (SawlogCalc calls a list of logs a 'tally', to avoid confusion with species lists, lists of lists, etc. The T+ is the Tally Add button.) The button text will change from 'new' to '1' to show one log in the list. If your next log is the same length and species, you only need to enter the diameter and tap T+ to add it to the tally. On a tablet, the Tally List is already showing and you can watch the running totals increase with every log added. On a one-pane device, press the list button (bottom right of screen) or use the menu to switch to the Tally List screen.



  1. Sawlog screen
  2. Tally List screen
  3. One Tally screen
  4. Edit Log screen
  5. Tree Species
  6. Preferences (settings)
  7. Free and Pro versions
  8. Requirements for SawlogCalc 3.2

1) Sawlog screen

This is the starting screen, where it all begins. Pressing the 'home' icon or the 'calc' icon will bring this screen up (if it isn't already showing). The species, log rule, length and small diameter of a sawlog are entered here, to calculate an estimated weight and the number of board feet for the sawlog. A price per board foot can be entered here, or left blank. A note can be entered here, or left blank. The T+ button (Tally Add) will add the currently displayed sawlog to the active sawlog tally.


To change the length, diameter, log rule or species, tap the button where the current value is displayed, then enter the new value. For example, tap the length. It will turn orange (to show that numbers entered will go there) and the weight, yield (bd ft) and larger diameter will go blank because they depend on the length. Tap 8 (sp) 1 = to enter a length of 8 feet 1 inch. The L: button now displays 8’ 1” and the weight, yield and large diameter are updated.

To enter a fraction, tap the space button (sp) after the whole part. For example, nine and a half feet is entered as 9 (sp) 1 / 2 ft =

Since sawlogs are often cut to the same length but the diameter is always changing, entering a measurement without tapping anything first will change the small diameter.

Measurements can be entered in a variety of formats:

Note: 8 (sp) 1 can only be feet/inches, so the feet button and the inches button aren’t needed. Also, if no units are entered at all, a diameter will be taken as inches and a length (up through 24) will be taken as feet.

Pressing: ft (feet button) or in (inches button) when nothing is being changed will display the last measurement entered in feet or inches. This can be handy to convert between feet and inches. Try it twice for inches or three times for feet to see all the possibilities.


Tapping the species will bring up the short list. Initially this will be empty, except for the CUSTOM LIST and FULL LIST lines (which will always be at the bottom of the list). Tap this to see (amazingly enough) the custom list or full list of species. Tapping any species in a list will mark it checked, which adds it to the short list. Touching a species and holding (long press) will select that species as the current species without affecting whether it appears in the short list, and will return to the sawlog screen. As an example, tap Ash, White. It will now be checked, and will appear in the short list the next time the short list comes up. Long press Aspen, Bigtooth: the sawlog screen will be displayed with bigtooth aspen as the current species. Bigtooth aspen will not appear in the short list (it wasn't checked).


The T+ button shows the number of logs currently in the active tally. Pressing the button adds the currently showing log to the active tally. In the tally, each log has a “serial number”. This comes from the # button, and can be changed if desired. It will go up by one every time the T+ button is pressed. For example, press # 1 0 0 = . The “serial number” will change to 100. Press T+, the log showing will be put in the active tally with a serial number of 100, and the number in the # button will advance to 101. The next press of T+ will put a log in the active tally with a serial number of 101. You can set the serial number to a any number you like. Any time a new tally is created, all lists of logs will be scanned and the serial number will be set to highest serial number found plus one, to make sure there are no duplications.

A long press on the T+ button will change to the Tally screen, showing the active tally


The large diameter of the sawlog is estimated to increase by 15% for every eight feet of log length. This value (shown in the calced button on the Sawlog screen) is calculated whenever a new length or small diameter is entered. If a different large diameter will give a better estimate of weight, press the calced button and enter the new large diameter. The button will change to show D2: and the new value.

The weight given by the log weight calculator is a rough estimate. Like any estimate, it is wrong, possibly by a lot.The density of green wood can vary wildly from one tree to the next within the same species, or even within the same tree. The density values in the Master Species List are average for North America. Rot, disease, growing conditions, bark thickness, height of the wood above ground in the tree, time of year, geography and a host of other factors all change the density of the wood. For this reason, the result is rounded to make it clear that this is not an exact value:

The four flavors of board yield are Doyle, Scribner Decimal C (formula), Scribner Decimal C (table), and International ¼ inch. The Scribner formula will not always match the original Scribner table: a log that is 16 feet long and 6 inches diameter small end will come up as 10 board feet using the Scribner Decimal C formula but will be 20 board feet from the Scribner Decimal C table. The Scribner table will handle logs from 3 feet to 20 feet in length and 3 inches to 40 inches in diameter. Anything outside this range will show ERROR for board feet.

2) Tally List screen

This screen shows a list of all the tallies. Pressing the 'list' icon in the action bar will bring this screen up if it isn't already showing. Each tally shows a tally name, the date the tally was created, number of logs, total yield (bd ft), total estimated weight and the sum of log costs if any log has a price set. Tapping a tally brings up a list of choices that apply only to that tally:

At the bottom of the screen is a row for buttons:

  1. new tally will create a new tally, make it the active tally (so that the T+ button on the Sawlog page adds logs to it) and display the new tally in the One Tally screen if it is showing. When the tally is created, the creation date is stored with it. (Note that older tallies from the previous version of SawlogCalc will show ??/??/???? for the date.)

  2. If it is showing, undelete will recover a tally that was previously deleted. The button appears when a tally is deleted, and will show for one hour of app run time. Confusing as this sounds, it just means that no matter how many times you exit and restart SawlogCalc, the undelete button will show up on the tally list until the app has run for at least an hour. Example: delete a tally, button appears. After 15 minutes, quit app. Come back to it a week or two later, run it for another 30 minutes. Quit again. Some time later, start the app again. Use it for 15 minutes. The undelete button still shows, but if you quit the app, it will be gone the next time you start it up again, because the app has run for 15 + 30 + 15 minutes, one hour.

3) One Tally screen

The details of one tally are shown here, with the totals for the tally shown in the header at the top, with a list of all the individual logs in the tally below. Tapping the header brings up the same choices as in the Tally List screen. Tapping an individual log brings up the following choices:

4) Edit Log screen

Reached by tapping a log from the One Tally screen and selecting Edit log, this screen can be used to change the values for a sawlog that has already been entered. If any changes are made, a Save button appears. When the Save button is pressed, the sawlog in the tally is changed. If Cancel is pressed, changes are thrown away; the sawlog in the list is untouched.

5) Tree Species

The tree species on the Sawlog screen is used to estimate the green weight of the sawlog, and is useful if tallies are used for record keeping. It would be clumsy to have to scroll through more than a hundred species every time you wanted to change, so tapping the species button will bring up a short list. You can add the species you use most to the short list, and still get to the full list or custom list to choose a less commonly found species with a long press.

The full list is fixed and can't be changed. Each species density is an average of North American values for the green weight, pulled from several sources. The different sources usually agree, but a few species (Black Walnut is an example) have significantly different values from place to place. The highest density was chosen when sources didn't agree, to err on the side of caution.

The custom list is yours. It will start out with Osage Orange in it as an example. Delete it, change it, add to it, you can edit this list to contain whatever species and densities you want.

When SawlogCalc first comes up, the species button will show "Alder, Red" just because that is the first species in the full list. A tap on the button will bring up the short list, which shows "CUSTOM LIST" and "FULL LIST". To set up the short list, tap "FULL LIST". You will get a long scrollable list of species. Tap any that you want to appear in the short list, which will mark the check box beside the name. You can also long-press a name, which will bring you back to the calculator page with that species selected. From the short list you can also tap "CUSTOM LIST" and do the same set up or long press, though the list will only have Osage Orange in it until you change it.

At the bottom of the Custom Species List is a button, Edit custom list. Pressing this will bring up the list of custom species in a screen where every name and density can be changed. Tap a name or density to change it. Density is in pounds per cubic foot, and needs to be entered as two digits. Note: there is no validity checking on the value entered for density. If you wish to enter 0 1, it will be accepted. Since one pound per cubic foot is roughly the density of styrofoam, the weight of a log calculated using this custom species is not likely to be a useful estimate. But it's up to you.

There will also be a blank line at the bottom of the list, with the light gray text "new name" showing. You enter new species in a blank line like this. The "new name" shows up any time the name of the species is blank. The button add new to end at the bottom of the list will add one new blank line per press. Don't worry about extras: blank lines are trimmed off the end of the list when you leave it. To set up the Custom Species List, press add new to end, tap the new blank name, type in a name, tap 'next' or the density, and type in the density. Repeat for all the custom species you want, tap 'back' to see your new Custom List, tap to check mark those that you want to appear in the short list. Custom species appear at the top of the short list, above any species check marked in the full list.

6) Preferences (Settings)

Preferences can be reached by tapping the 'settings' icon in the action bar (gear shape).

  1. Audible Sets the level of audible feedback that sounds when a button is pressed. Choices range from none to 100% (full volume)
  2. Haptic Sets the level of haptic (tactile) feedback when a button is pressed. Choices: none, low, medium, high. What each setting does may vary from one device to another, and some devices may not support haptic feedback at all.
  3. Rotation Controls the orientation of the display. If Enabled, rotating your device will also change the calculator display.  Selecting Portrait will always take the long direction of the screen as vertical, regardless of any orientation sensor. Landscape will always take the long edge of the screen as horizontal.
  4. Screen layout Android devices come in a plethora of shapes and sizes. On a small phone, you might only want to see one thing at a time. On a tablet, three can easily be shown.  Screen size of Auto will use measurements from the device to pick the most likely best fit. You can also force the display to show the number of panes that you prefer. Each pane will show one thing (sawlog calculator, full species list, etc). One, two or three panes can be chosen, or "one tall, two wide" which will show one pane in portrait orientation or two in landscape.
  5. Screen Time out Your android device has a setting for shutting off after being idle for a selected amount of time. Screen: Timeout will follow that setting and shut down. Screen: Keep on will ignore the setting and the screen will stay on as long as BoardCalc is showing.
  6. Help Text size The help text can be shown in different sizes. Smaller fonts are harder to read but show more on the page. Choices range from 12 to 20. This text size can also be set from the Help page context menu (long press).
  7. To: anything entered here will always be pre-loaded in the To: field of the export email. If this is left blank, nothing will be pre-loaded.
  8. CC: anything entered here will always be pre-loaded in the CC: field of the export email. If this is left blank, nothing will be pre-loaded.
  9. BCC: anything entered here will always be pre-loaded in the BCC: field of the export email. If this is left blank, nothing will be pre-loaded.
  10. Subj: anything entered here will always be pre-loaded in the subject line of the export email. If this is left blank, nothing will be pre-loaded.
  11. Export text: if yes, the tally totals and log values will be loaded in the body of the email in human-friendly text, columns separated by spaces.
  12. Export CSV: if yes, the tally totals and log values will be loaded in the body of the email as lines of comma-separated values. This is hard for a human to read, but works well with spreadsheets and documents.
CSV example: to move the data to Excel,
  1. copy the CSV text from the email
  2. select a single cell in the Excel spreadsheet
  3. paste (which should put the text into one column)
  4. select the column if it isn't already
  5. in the Data Menu choose Text to Columns to bring up a wizard
  6. when the wizard asks for delimiters, select comma
  7. when the wizard asks for data format, use General
  8. when the wizard finishes, the Tally should be neatly spread out in the columns of the spreadsheet with headings above the columns

7) Free and Pro versions

SawlogCalc comes in Personal (free) and Pro (paid) versions. There is no advertising in either version. Both share the same screens and almost the same functionality. The Personal version is limited: it will not export a tally, or keep Custom Species, and all tally information evaporates (and is lost) when you leave the application, rotate the device, are interrupted by a phone call, etc. If you only need to deal with one log at a time, or temporarily add up a tally of logs, the Personal version will work well. If you need to retain tallies or export them, the Pro version is required.

8) Requirements for SawlogCalc 3.2