The Math Behind the Materials
Every number in these guides comes straight out of the same formulas that power our calculators, cross-checked against Quikrete coverage charts, IRC code tables, and supplier spec sheets. No hand-waving, no "it depends" without the actual numbers underneath it.
How Many Bags of Concrete Do I Need?
The 10x10 slab math, when to switch from bags to a ready-mix truck, and why your wheelbarrow arm cares about the answer.
ConcreteHow Much Concrete Per Post Hole?
Fence posts, deck piers, and the hole-diameter trap that costs people a whole extra pallet of bags.
RoofingHow Many Bundles of Shingles Per Square?
Three bundles a square, most of the time. Here is what pitch, hips, and overhangs do to that number.
LandscapingHow Much Mulch Do I Need?
Bags versus bulk yards, the 3-inch rule, and where bagged mulch quietly stops making financial sense.
CarpentryHow Many Studs Do I Need for a Wall?
The length-divided-by-spacing-plus-one rule, what corners and doors really add, and why you should buy 10% extra anyway.
CarpentryHow Many Deck Boards Do I Need?
Row-by-row layout math for a 12x12 deck, screw counts, and the spacing question everyone gets backwards.