construction calculators

Every calculator runs entirely in your browser — nothing you type is sent anywhere.

Concrete Volume & Bag Estimator

Estimate the cubic footage, cubic yards, and number of pre-mix bags needed for a rectangular concrete slab or footing — including an optional waste allowance.

Board Feet Calculator

Calculate board feet of lumber from thickness, width, length, and quantity.

Roof Pitch & Rafter Length Calculator

Find rafter length, slope factor, and roof angle from the pitch (rise per 12) and building span.

Stair Rise & Run Calculator

Lay out a stair: number of risers, actual riser height, tread count, and total run from the total rise.

Right Triangle (Pythagorean) Calculator

Solve a right triangle: enter any two sides and get the third side plus both acute angles.

Footing Concrete Volume Calculator

Estimate the concrete needed for a strip or continuous footing from its length and its width and depth in inches — with an optional waste allowance.

Column & Sonotube Concrete Volume Calculator

Find the concrete volume for round columns or Sonotube piers from the tube diameter, height, and quantity.

Concrete Cost Estimator

Estimate ready-mix concrete cost from the volume in cubic yards and your delivered price per yard, with an optional waste allowance.

Gravel & Aggregate Tonnage Calculator

Convert an area and depth into tons of gravel, sand, stone, or topsoil using the material's density — for driveways, base, and fill.

Rebar Weight Calculator

Find the total weight of reinforcing bar from the bar size (#3–#11) and total linear feet, using ASTM standard unit weights.

Rebar Grid Count & Spacing Calculator

Lay out a slab reinforcing mat: how many bars run each direction at a given spacing and edge cover, plus the total linear feet.

Boards Needed (Coverage) Calculator

Count the boards to cover an area — decking, siding, or flooring — from the board width, length, and a waste allowance.

Wall Stud Count Calculator

Estimate the number of wall studs from the wall length and on-center spacing (16 or 24 in).

Circle & Pipe Circumference / Area Calculator

Get the circumference and cross-sectional area of a circle or pipe from its diameter.

Area Calculator (Rectangle, Circle, Triangle, Trapezoid)

Calculate area for a rectangle, circle, triangle, or trapezoid — fill in only the dimensions your shape needs.

Volume Calculator (Box, Cylinder, Sphere, Cone)

Calculate volume (and gallons) for a box, cylinder, sphere, or cone — fill in only the dimensions your shape needs.

All results are an engineering estimate — not for custody transfer. Field measurement and certified tables govern.