# Online demonstration of roof rafter calculator

With this online calculator, it is possible to workout rafters for your roof. It can be used for making calculation of rafter length, board size, quantity, cost per board and total cost of lumber.

The diagram located at the right is applied to provide roof dimension precisely as well as work out board length more perfectly.

Depending on the foot print (length and width) of your home and roof slope, the calculator can perfectly compute all Rafters and Ridge boards. It will facilitate you to create a list of materials required for your roof framing on the basis of board sizes and board lengths, employing materials prices quoted from several lumber yards and building material suppliers.

When the value of the slope (pitch) of your roof is unknown, this slope calculator tool will be very effective. This rafter calculator can function in Imperial measuring system (feet / inches).

Rafters belong to the structural support of any roof, and this tool will allow you to compute roof rafter (truss) length, in accordance with house gable side width (span), roof slope and length of the overhangs. You can also obtain number of rafters required to built up your roof, according to house footprint, as well as cost per rafter (depending on rafter size) and total cost.

Guidelines to apply Rafter Calculator:

1) Put in house footprint: Length is specified in the roof eave (gutter) side. Width or Span is specified in the gable side of the roof that is useful for working out rafter length and cost.
2) Enter overhang length: Most houses contain overhangs (soffits) to safeguard the house exterior walls and foundation from water overflow from the roof. Provide preferred overhang length - it will impact your rafter length and lumber required for the job.

3) Put in roof pitch / slope: Roof pitch refers to the value of roof rise over roof run, applying 12 as the base for roof run. As for instance, if your roof gets higher 5" for every 12" of run, provide 5 as roof pitch. If your roof pitch remains in degrees, the roof pitch calc can transform degrees to "pitch" value.
4) Choose rafter spacing and width:
Rafter spacing (and roof length) are applied to find out the quantity of rafters required for your project.

Lumber size/ width (2x8", 2x10" or 2x12" boards) should have been utilized to calculate cost of each rafter along with the total cost (irrespective of local sales tax).

To make calculation online, click on the following link www.roofcalc.org