Builder Fraction Calculator – David King

Feet and inch construction calculator designed for builders, carpenters, framing contractors, architects, and engineers.

Basic math :

Use familiar numbers like standard calculators or use feet, inches, and fraction format.

Wizards :

A collection of guides that prompt you through complex construction math.

Diagonal :
For squaring up layouts, solving for pitches along with degrees, and bastard pitch rafters.

Rafter :

For common rafter applications where the roof width, the pitch, and the thickness of the ridge are entered to result in the length of the rafter, the rise and the run.

Lean to rafter :

For applications when the run and the roof pitch are known.
Results are the length of the rafter and the rise.

Rafter known rise :

For applications when the rise and the roof pitch are known.
Results are the length of the rafter and the run.

Jack rafter :

For applications when one jack rafter is known along with its roof pitch and the pitch of the other side.

High – low wall rafter :

For applications where one rafter goes on a higher wall than the other rafter and they are on the same pitch.

Hip roof :

For applications on hip roof framing when the main criteria are known:

Roof width, main pitch, side pitch, main cornice width, side cornice width, ridge thickness, and the hip thickness.

Returns all concerning measurements.

Stairs :

For residential applications when 7 3/4″ is the maximum riser.

Roof decking :

Custom built to solve for any unknown side of a piece of roof decking on any slope or combination of roof pitches with incredible accuracy.

Gable studs :

For applications where one gable stud is known along with the pitch of the rake. Go from the short one up or the long one down.