Construction & Carpentry Calculators
Material quantities, layout dimensions, and code limit checks for roofing, concrete, stairs, rebar, drywall, and masonry. Each calculator has a guide that shows the formulas behind the numbers.
Eight calculators for common takeoff and layout jobs
Each calculator runs in your browser and redraws its diagram as you change a value.
Roof Pitch & Rafter
Rafter length, angles, rise/run
Concrete Slab & Footing
Cubic yards, bags, premix trucks
Stair Stringer Layout
Riser height, tread depth, code check
Rebar Weight & Grid
Linear footage, total weight, lap splice
Brick & CMU Block
Brick count, mortar bags, sand
Drywall Sheets & Mud
4x8, 4x12 sheet count, screws, mud
Roofing Squares & Shingles
Square count, bundles, underlayment
Material Waste Factor
Industry contractor cutting allowances
Reference charts and ordering guides
Concrete
Concrete Yardage Chart: Slab Volume, Bags, and Truck Loads
A slab volume chart in cubic yards and 60 lb / 80 lb bags by size and thickness, plus how to order ready-mix, what to add for waste, and where short loads cost extra.
Reinforcing steel
Rebar Size and Weight Chart (#3 to #11) with Lap and Cover Rules
Diameter, weight per foot, and area for ASTM A615 rebar #3 through #11, with weights for common slab grids, lap splice rules of thumb, and concrete cover requirements.
Stairs
IRC Stair Requirements: Rise, Run, Headroom, and Handrails Explained
The IRC R311.7 stair limits in plain terms: maximum riser, minimum tread, headroom, width, nosing, handrail height, and how to lay out a stair that passes inspection.
Roofing & framing
Roof Pitch Chart: Angle, Slope Multiplier, and Rafter Length per Foot of Run
A roof pitch chart from 1:12 to 18:12 with angle, percent grade, slope multiplier, and rafter length per foot of run, plus minimum pitch limits for common roof coverings.
Interior finish
How Much Drywall to Order: Sheets, Screws, Tape, and Joint Compound
How to count drywall sheets for walls and ceilings, which sheet length to buy, and how much screws, tape, and joint compound a room needs, with sample room takeoffs.
Roofing & framing
Roofing Squares and Bundles: How to Order Shingles for Any Roof
What a roofing square is, how pitch and roof shape change the shingle count, and how to order bundles, underlayment, starter, and ridge cap with sample takeoffs.
Masonry
Brick and CMU Block Quantities per 100 Square Feet of Wall
Units per square foot for modular brick, queen, king, and CMU block, with mortar and sand allowances, opening deductions, and how joint thickness changes the count.
Estimating
Construction Waste Factors by Material: What to Add and When
Typical waste percentages for tile, flooring, drywall, concrete, siding, and masonry, what pushes each one higher, and how to avoid adding waste twice.
How the calculators work
The formulas are standard geometry and published unit factors. The guides show them step by step.
Calculated in your browser
Results update as you type. The values you enter stay on your device and are not sent to a server.
Diagrams that follow your numbers
Rafters, stair stringers, and rebar grids are redrawn to scale from your measurements, so a typo shows up as a wrong-looking shape.
Code limits where they apply
The stair calculator flags risers above 7.75 in. and treads below 10 in. (IRC R311.7). Rebar laps use a 40-diameter rule of thumb, not a design value.
Habits that prevent short orders
- Work out the net quantity first, then apply waste once. Applying it in two places overorders.
- Round up to whole sheets, bags, bundles, or yards after the waste step, never before.
- Check whether a dimension is nominal or actual. A 4 in. by 8 in. by 16 in. block is a different size than its name.
- Confirm limits with the local building department. Adopted code editions and amendments differ by jurisdiction.
Read the editorial policy for sources, known approximations, and how corrections are published.