Although calculators that work with fractions have been available for years, most are not oriented towards fine woodworkers, quilt makers or other craftspeople. They are also loaded with unneeded features and complications. How often does a furniture maker need to calculate the length of a rafter based on a roof pitch?

In spite of almost all fractions being measurements, most calculators require the denominator to be entered instead of providing dedicated buttons for the 1/2, 1/4, 1/8, etc.

When working in fractions, there are inevitable round-off errors. These errors may be inconsequential but can sometimes accumulate to generate large, noticeable layout problems.

For example, if a headboard design requires 19 evenly spaced spindles across a length of 58 7/16”, the spacing is 3 1/16”. If you layout those 19 spindles spaced 3 1/16” apart, the last one will be off by 1/4” due to the rounding error. When doing layout such as this, a woodworker needs to know the cumulative error. This allow the error to be distributed in an acceptable way.

The same sort of cumulative error is a problem when creating quilts and working with small pieces.

For operations that may have errors, this error is displayed on the tape. The tape allows previous results to be viewed and recalled for modification.

Using the paradigm of old-style paper tape desktop calculators, both WoodworkerCalc and QuiltCalc can save sequences of calculations as “tapes”. These tapes can be retrieved later for review or as a basis for more calculations.

Although a woodworker may not need to calculate the pitch of a roof, they do triangle calculations frequently. What angle should the table saw be set to in order to cut a 1/4” bevel on a 4” post? The Woodworker’s Calculator has a page for performing every flavor of triangle calculation.

You can download the WoodworkerCalc and QuiltCalc from the ITunes store.