Guides & Reference Tables
Our calculators give you a number. These guides explain where those numbers come from: the waste allowances built into the results, the unit conversions the trades actually use, and the code requirements that constrain them.
How Many Bags of Concrete in a Cubic Yard (40, 50, 60 and 80 lb)
A cubic yard is 27 cubic feet and an 80 lb bag yields 0.6 of them, so a yard is 45 bags. This reference puts all four bag sizes in one table by yard, half yard, quarter yard and cubic foot, then covers where the yield figure comes from, what a pallet holds, and the point at which a ready-mix truck becomes cheaper than the bags.
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How Much Concrete for a Garage or Shop Slab (12x20 to 40x60)
A 24x24 garage floor at 4 inches is 7.82 cubic yards, ordered as 8, one truck. This guide is built around the ready-mix order: yards and mixer loads for every common garage and pole-barn size at 4, 5 and 6 inches, what to specify, how the quarter-yard rounding works, and which parts of the foundation the slab figure does not include.
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How Much Concrete for a Patio Slab (10x10 to 20x20)
A 12x12 patio at 4 inches is 1.96 cubic yards, ordered as 2, and it arrives on a truck because 89 bags is not a patio anyone finishes well. This guide follows the pour in order: thickness, the ready-mix order and its short-load fee, the fall away from the house, the joints, the mesh, the broom finish and the cure.
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How Much Concrete for a Shed Slab (8x8 to 16x20)
A 10x12 shed slab is 1.63 cubic yards of concrete, which is 74 bags of 80 lb mix or a short ready-mix order. This guide settles the slab-or-gravel-pad question first, tables every common shed footprint at 4 and 6 inches, and covers the base, vapor barrier, anchor bolts and joints that go with a small pour.
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How Much Concrete for Fence Posts, Deck Footings and Sonotubes
Post holes are small pours that add up fast: a ten-post privacy fence is 30 bags of 80 lb mix. This guide goes hole by hole, from an 8 inch mailbox footing to a 16 inch Sonotube pier, with bag counts in 50, 60 and 80 lb sizes, what the post itself displaces, and when a dry pour is and is not acceptable.
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Concrete Slab Cost in 2026: Bags, Ready-Mix and Labor by Size
A 20x20 slab at 4 inches is $815 of ready-mix at $150 a yard or $1,593 in 80 lb bags, and $2,400 to $4,800 hired out. This guide prices six slab sizes three ways, explains the per-yard rate and the short-load and standby fees around it, lists the base, steel, forms, pump and saw cuts a concrete price leaves out, and shows how to read a quote.
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How Thick Should a Concrete Slab Be: Patio, Shed, Driveway and Garage
Four inches covers most residential slabs, but a driveway that sees pickups, a shop floor with a lift or an RV pad each want more. This guide goes use by use through the conventional thicknesses, the 3.5 inch code floor, why thickness, strength and reinforcement are separate decisions, and exactly how much concrete each extra inch adds on a 12x12 slab.
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Cubic Yards to Tons: Gravel, Sand, Topsoil and Mulch Conversion Chart
A cubic yard of gravel weighs about 1.4 tons, topsoil about 1.1, and wood mulch under half a ton, so the conversion is never one number. This chart gives tons per cubic yard for the bulk materials a yard actually sells, works 1 to 10 yards in both directions, and keeps the moisture and compaction adjustments separate from the density itself.
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How Much Decking for a 10x10, 12x12, 12x16 or 16x20 Deck
A 12x16 deck takes 39 boards of 12 ft stock or 30 of 16 ft, and the difference is not the lumber, it is where the butt joints land. This guide puts every common deck size in one table at both lengths, adds the diagonal counts at 12 inch joists, and covers the joists, screws and offcuts the board count leaves out.
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How Much Gravel for a Driveway (by Length, Width and Depth)
A new gravel drive is a 12 inch stack of three layers and a tired one needs a 4 inch top course, and the tonnage differs by three times. Tables for 50 to 300 ft drives at 4, 6 and 12 inches, the case for 12 ft over 10, crown and drainage, and how many truckloads the order turns into.
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How Much Gravel for a Shed Base (8x8 to 16x20 Pads)
The pad under a shed is a foot bigger than the shed each way, and this guide follows that pad from the string line to the last pass of the compactor: tons, cubic yards and material cost for eleven pad sizes at 4 and 6 inches, crusher run against clean stone, the frame, the fabric, and the delivery charge that dwarfs the stone on a small pad.
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How Many Pavers for a Patio (8x10 to 20x20, by Paver Size)
Nine patio sizes from 8x10 to 20x20 against six paver sizes, with the running-bond and herringbone counts already carrying their waste. Then the base and sand under each size, why the order rounds to whole pallets, and the two things at the edges that the tables leave out.
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Rebar Size Chart: Diameter, Weight and Spacing for Slabs and Footings
A size chart for #3 through #8 rebar with the diameter, metric name, cross-section, weight per foot and 20 ft stick weight of each, then the parts of the job the chart feeds: which bar goes where on a house lot, grid spacing read as steel per foot, the 3 inches of cover ACI 318 sets against earth, laps, chairs, mesh against bar, and a worked weight estimate for a 20x20 slab.
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Material Waste Factors
Every quantity calculator gives you a geometrically perfect number, and that number will leave you short. This guide covers typical waste allowances by material, and why compaction and settling are different problems that need separate allowances.
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Mortar, Grout & Core Fill
Mortar bonds the units, grout fills the cores, and standard concrete mix does neither well. This guide sets the three side by side, then works through how much of each a job takes, including why a partially grouted wall needs roughly a third of the fully grouted figure.
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Paint Coverage Rates
A gallon of architectural paint is commonly labelled at 350 to 400 square feet, and that figure assumes a smooth, sealed, primed surface, one coat, applied with a roller. This guide starts with that number and then works through each condition that pulls the real rate away from it, ending with how to turn a corrected rate into cans.
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Paver Base and Bedding
A paver patio is a stack of five layers, and each one can fail on its own. This guide follows the stack in the order it gets built, from the subgrade up: how deep the base goes for a patio against a driveway, which aggregate belongs in it, and why the inch of sand above it is not a levelling course.
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Construction Unit Conversions
The trades measure in units that rarely match how material is sold. This is a reference for the conversions that come up most, covering cubic yards to tons, roofing squares, board feet, and bag counts, including why any yards-to-tons conversion needs the material's density.
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Stair Code Requirements
The IRC caps residential risers at 7 3/4 inches and requires treads of at least 10 inches, but the rule that fails inspections most often is uniformity: no more than 3/8 inch of variation between the tallest and shortest riser in a flight.
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