Pourwright Concrete Calculator

What it does

Pourwright is a concrete and masonry calculator for concrete finishers, masons, contractors, estimators and do-it-yourselfers. It works like a hardware calculator: a concrete-grey chassis, real keys and a clear LCD, with each answer labelled so you know what you are reading.

Worked examples

• Slab volume. 20 x 10 ft slab, 4 in thick -> 2.47 cu yd.
• Premix bags. Same slab with 5 % waste -> 117 bags of 80 lb.
• Rebar grid. Same slab, #4 at 12 in, 3 in cover -> 11 bars along the length.
• Block wall. 40 x 8 ft wall less a 3 x 7 ft door -> 354 blocks (8x16).
• Steps. Three steps 4 ft wide, 7 in riser, 11 in tread -> 0.48 cu yd.
• Metric bags. 6 x 3 m slab, 100 mm thick, 5 % waste -> 152 bags of 25 kg.

How it's calculated

Every trade key and the formula behind it, as shown in the app's key guide. A second legend is the shifted function.

Len WasteLength / Waste percent

Stores the typed slab, footing or wall length, else recalls it; shifted stores the typed waste percent added to volumes, bags and masonry (5 % when unset).

Wid QtyWidth / Quantity

Stores the typed width (a rectangle pour, or the stair width), else recalls it; shifted stores how many identical footings or piers the volume covers.

Thk DiaThickness or depth / Column diameter

Stores the typed thickness, depth or column height; shifted stores a round column diameter, so Vol gives π × d² ÷ 4 × height until a width is typed again.

Vol WtVolume / Weight

Volume = length × width × thickness × quantity in cubic yards (cubic metres), then with waste; a typed volume is stored. Shifted gives the weight at 150 lb/ft³ (2400 kg/m³).

Bags OrderPremix bags / Ready-mix order

Premix bags = volume with waste ÷ typical yield (80 lb ≈ 0.60 cu ft, 60 lb ≈ 0.45, 25 kg ≈ 12.5 L; check the bag). Shifted rounds the ready-mix order up to ¼ yd³ (¼ m³).

Rebar BarRebar grid / Bar size or cover

A typed length sets the spacing; else a two-way grid for the slab: bars each way = ⌈(side − 2 cover) ÷ spacing⌉ + 1, lengths and weight. Shifted: a number picks the bar, a length the cover.

Stair TreadConcrete steps / Tread depth

A number sets the steps, a length the riser; else solid steps to grade = width × riser × tread × n(n + 1) ÷ 2, with waste and bags. Shifted sets the tread (11 in, 280 mm when unset).

Area OpenWall area / Openings

Stores the typed wall area, or length × a typed height; else recalls it or shows length × width. Shifted adds a typed opening area to subtract (typed 0 clears).

Block BrickBlock count / Brick count

Blocks = net wall area × 1.125 per sq ft (8×16 in) or 9.88 per m² plus waste, then typical mortar bags; a typed area is stored. Shifted counts modular bricks at 6.75 per sq ft (59.3 per m²).

Quantities are estimates. Bag yields, mortar rules and densities are typical published figures: check the yield printed on the product you buy, and confirm orders and reinforcement with your supplier and the project drawings. The developer accepts no liability for loss or damage arising from use.