20 calculators across four trades. Each one shows its formula, its sources and every assumption behind the number.
Area of rooms and surfaces
Add and subtract tape measurements
Volume for ordering material
Multi-shape area with waste
Volume for any pour shape
Volume, bags and weight for a slab
Bag counts by product and size
Continuous and pad footings
Ready-mix and bag pricing
Grid spacing, bars and weight
Concrete per hole, posts subtracted
Full takeoff for a gable roof
Pitch, angle and slope factor
Sloped area, hips and ridges
Bundles and squares by product
Common rafter cut list
Risers, treads and headroom
Cut list, throat and stock
Lumber volume and cost
Boards, gaps and screws
