iPhone Screenshots


ConCalc (CONtractor's CALCulator) is a feet, inch, mm, and fraction calculator with a much improved triangle solver also included. ConCalc was designed for individuals who frequently perform computations with imperial fractions (draftsmen, estimators, engineers, architects, and or construction personnel).

The objective of ConCalc is to provide a Foot-inch calculator that would be intuitive, easy to use, and fast. Since most professionals who deal with fractions, also regularly solve triangle problems, ConCalc also solves all types of triangle problems (right triangles, acute, obtuse, etc). Just provide three known values, and the calculator will produce the other three un-supplied values.

It is strongly suggested that you review the videos on youtube that demonstrate what this calculator does and how it works. Just search "ConCalc" on youtube or visit www.jplanaux.com.

Not sure that you want to purchase the application? View a video at our web site. www.jplanaux.com

Input in the FT-IN mode: The input key stokes have been optimized for the fewest key stokes possible and will be equal to the qty of digits that represent the feet, the foot mark, one key for the inch, and one key for the fraction. So for example, 12'-11 15/16" will be entered with 5 key inputs: "1", "2", "FT", "11", and "15/16".


The user is required to provide three of the six parts (two for a right triangle: the third angle would be set to 90 degrees) which make up a triangle. The input to this calculator is through the Calculator view:

Step 1: Enter three pieces of data using the appropriate side or angle button.
Step 2: Press "Solve Triangle"
Step 3: View results.

Note: The format of the output is determined by the current mode (indicated by the blue button on the calculator). For example, if the mode is decimal, the output will be decimal. If the mode is FT-IN, then the output will be FT-IN. Angles are always output as decimal degrees.

What's New

Version 2.0.1

Revised button layout to utilize mote of the available screen

Customer Reviews



The application has good potential. I like the basic idea behind the calculator but I am seeing a few bugs that need to bee worked out. It has a hard time changing between “ft-in” mode and “inch” mode sometimes. I have to press the button several times to get it to switch. I would like to see 1/64” made available in the app as well. Sorry, but the colors are lousy, give me some optional colors please.

Don't buy this app!!!

nine finger carpenter

The app doesn't seem to work with OS 4.x well. I can't get the Triangle or Tri Sol modules to allow input and the calculator has hung multiple times as I have tried to use it. It sometimes will work for a few calculations then will hang until you restart. Sometimes trying to put in a dimension with inches over 10 it will decide it has to be a fraction and not allow input of inches ten or over. There isn't any support so I guess I'm out of luck.

Nice interface


It took a few minutes to get used to the color scheme, but now it's very functional and clear.


Jean-Paul Lanaux
999.4 KB
Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.
Age Rating
Rated 4+
© ConCalc by Jean-Paul Lanaux


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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