Every calculator here is plain arithmetic you can check with a pencil. The factors (bag yields, bricks per square foot, bar weights, coverage rates) come from the makers and trade groups who publish them.
Our rules
- Show the math. Every calculator page explains its formula and works an example.
- Published factors only. Where a number depends on a product, we use the maker’s published figure and name it.
- You can override it. Weights per yard, densities, bag sizes and waste are inputs, because your supplier’s numbers beat ours.
- No guessing at code. Where building codes matter (stairs, footings, structural walls) we say so and point you to your building department.
- Nothing is sent to us. The calculators run in your browser. Your project list stays on your device.
Sources we use
- Quikrete Concrete Mix (No. 1101) data sheet: bag yields 0.30, 0.375, 0.45 and 0.60 cu ft for 40, 50, 60 and 80 lb
- Quikrete: Setting Posts in Concrete (hole 3 times the post width, depth 1/3 to 1/2 of the above-ground post, plus 6 in)
- Quikrete Fast-Setting Concrete Mix data sheet (sets in 20 to 40 minutes)
- US Navy construction training manual: conventional concrete weighs about 150 lb per cubic foot
- ACI 308R basic curing period (7 days above 50°F), as summarized in US NRC concrete training slides
- Brick Industry Association, Technical Note 10: Dimensioning and Estimating Brick Masonry
- Chaney Enterprises masonry catalog: mortar quantities per 1,000 units (25 bags and 5 tons of sand for 8 in block; 7 bags and 1.25 tons for modular brick)
- ASTM A615 bar weights as published by Carroll Supply (#3 0.376, #4 0.668, #5 1.043, #6 1.502 lb per ft)
- USG Beadex Lite taping compound submittal: about 9.4 gal per 1,000 sq ft of gypsum panels
- USG Sheetrock paper joint tape product data: about 370 ft per 1,000 sq ft of panels
- GAF Timberline shingle packaging: 3 bundles per 100 sq ft (Lowe’s product listing)
- City of Boise handout on IRC Section R311.7.5, stair treads and risers
- City of Des Moines residential stairs handout (2012 IRC): headroom 6 ft 8 in, handrail 34 to 38 in
- American Lumber Standard Committee comments on PS 20, dressed lumber size tables (NIST)
- UF/IFAS Gardening Solutions: Choosing and Installing Mulches
- ENERGY STAR: recommended home insulation R-values for existing wood-framed homes, by climate zone (based on the 2021 IECC)
- Belgard segmental retaining wall quick reference install guide (6 in compacted leveling pad, trench 12 in wider than the block, 6 in of the first course buried, 12 in of drainage aggregate behind)
- Nicolock retaining wall installation: bury the first course 10% of the wall height or at least 6 in
- Interlocking Concrete Pavement Institute: Construction Tolerance Guide (4 in minimum base for patios and walks, 1 in bedding layer)
Last checked 1 November 2026. If a maker changes a figure, tell us on the contact page and we will update it.