Spike's Calculators

Siding - Cladding

Fiber Cement Siding, Trim and Drip Cap Calculator

This fiber cement siding calculator will calculate the amount of boards needed to cover a wall. It will also calculate the amount of barge board, trim and corner board, plus the amount of nails needed to apply the siding based on nailing at 2' OC.

The calculator can be used for any type of siding that comes in boards of one length, including engineered wood siding.


Siding length, siding width and exposure need to be entered in decimal inches.
Most commonly used board is 12' x 8 ¼" with an exposure of 7"
Values that need to be entered for this size board would be:
Siding Length: 144"
Siding Width:  8.25"
Overlap: 1.25"
Exposure:  7" 

Fraction to Decimal Conversion Chart
1/8     0.125
1/4     0.25
3/8     0.375
1/2     0.5
5/8     0.625
3/4     0.75
7/8     0.875

Siding Exposure Lap

Items marked with * must be entered.

* Siding Length:   in.
* Siding Width:   in.
* Exposure:   in.
  Trim and Corner Width:   in.
  Number of Barge Board:   #
If you did not enter a trim value here the trim will be based on the values you entered for the sizes of the window(s) and door(s). You can add the trim width later but you will have to hit the calculate button.
Same goes for the Barge board. If you add the value here after the wall values have been calculated you will have to calculate each element again. It will give you a running total of Barge boards needed plus the required drip cap. At the same time it will reduce the amount of siding needed.

If there are window and/or door, the total amount of siding needed will be reduced as well as the nail count and house wrap needed when these items are calculated.
Add the element(s) you require with the following buttons or with the buttons on the added element.
The totals will be displayed in the box below.
Added elements must be filled in for the correct totals to be shown, use the Remove button to delete unused elements.

Your total amount of materials

Total amount needed:

   Total Siding: # of planks
   Total Barge: lineal feet
   Total Trim: lineal feet
   Total Drip: lineal feet
   Total Wrap: feet ²
   Total Nails: #

  • Note:
  • Siding needed does not include a waste factor.
  • House Wrap needed does not include amounts needed for overlaps.
  • Nails are based on nailing the siding boards at 600mm centers.
  • In addition this calculator does not provide the amount needed for joint flashing, tape and material for inside corners.

If you have any questions or comments please Contact Us
Privacy Policy
© 1998, VmNet.