# Material Guides

> Free calculators and technical guides for concrete, tile, flooring, drywall, decks, roofing and other home projects, with the formulas, assumptions and worked examples behind every number. Written by Eren Şimşir. US units throughout.

## Calculators

- [Concrete calculator](https://materialguides.com/concrete-calculator/): Cubic yards and bag counts for slabs, columns and post holes.
- [Gravel calculator](https://materialguides.com/gravel-calculator/): Cubic yards, tons and bags of gravel, sand or topsoil for any depth.
- [Deck calculator](https://materialguides.com/deck-calculator/): Deck boards, joists and screws, with real board lengths and offcuts.
- [Roofing calculator](https://materialguides.com/roofing-calculator/): Roof area from pitch, squares, shingle bundles and edge trim.
- [Fence calculator](https://materialguides.com/fence-calculator/): Posts, rails, pickets and bags of concrete for a wood fence with gates.
- [Brick and block calculator](https://materialguides.com/brick-calculator/): Bricks or concrete blocks and bags of mortar for a wall, plus pavers.
- [Mulch calculator](https://materialguides.com/mulch-calculator/): Bags or cubic yards of mulch, compost or garden soil for beds and raised beds.
- [Stair calculator](https://materialguides.com/stair-calculator/): Risers, treads and stringer length, checked against IRC limits.
- [Tile calculator](https://materialguides.com/tile-calculator/): Tiles and boxes, with grout joint and layout waste.
- [Flooring calculator](https://materialguides.com/flooring-calculator/): Boxes of laminate, vinyl plank or wood flooring, plus underlayment.
- [Drywall calculator](https://materialguides.com/drywall-calculator/): Sheets, screws, joint compound and tape for walls and ceilings.
- [Carpet calculator](https://materialguides.com/carpet-calculator/): Square yards to buy from a 12 ft roll, with seams, pad and tack strip.
- [Wallpaper calculator](https://materialguides.com/wallpaper-calculator/): Rolls of wallpaper counted strip by strip, with the pattern repeat.
- [Paint calculator](https://materialguides.com/paint-calculator/): Gallons and quarts for walls, ceilings and primer.
- [Square footage calculator](https://materialguides.com/square-footage-calculator/): Square feet of any room or shape, in sq yd, m² and acres too.
- [All calculators](https://materialguides.com/calculators/)

## Guides

- [Concrete Slab Thickness Guide: Patio, Driveway, Shed, Garage](https://materialguides.com/guides/concrete-slab-thickness/): How thick to pour a concrete patio, driveway, shed pad or garage floor, what each extra inch costs in concrete, and what goes under the slab.
- [How Many Bags of Concrete Do You Need per Fence Post?](https://materialguides.com/guides/concrete-for-fence-posts/): Bags of concrete per fence post by hole size and depth, for 4x4 and 6x6 posts, with the formula, a worked example for a whole fence and setting tips.
- [How Much Paint for a 12x12 Room? Coverage Chart by Room Size](https://materialguides.com/guides/how-much-paint-for-a-12x12-room/): A 12x12 room with 8 ft walls takes about 2 gallons of paint for two coats. See the coverage chart for 10x10 to 20x20 rooms, with and without the ceiling.
- [How to Measure an L-Shaped Room (and Other Odd Shapes)](https://materialguides.com/guides/how-to-measure-an-l-shaped-room/): Measure the square footage of L-shaped and irregular rooms by splitting them into rectangles, with diagrams, formulas for odd shapes and a worked example.
- [Tile Waste Factor by Layout: Straight, Diagonal, Herringbone](https://materialguides.com/guides/tile-waste-factor-by-layout/): How much extra tile to buy for straight, offset, diagonal and herringbone layouts, why small rooms waste more, and how waste changes the box count.

## Key figures used by the calculators

- Concrete bag yields (standard mix): 40 lb = 0.3 cu ft; 50 lb = 0.375 cu ft; 60 lb = 0.45 cu ft; 80 lb = 0.6 cu ft. 1 cubic yard = 27 cu ft.
- Tile waste allowances: Straight (grid) 10%; Offset / brick 10%; Diagonal (45°) 15%; Herringbone 20%.
- Paint: 350 sq ft per gallon default (labels range 250–400); door 21 sq ft; window 15 sq ft.
- Flooring waste allowances: Straight 10%; Diagonal 15%; Herringbone 20%; +5% for rooms with closets or many corners.
- Drywall: 4x8 sheet = 32 sq ft, 4x12 = 48 sq ft; joint compound about 9 gal and paper tape about 370 ft per 1,000 sq ft of board; screws 12 in apart on ceilings, 16 in on walls framed 16 in on center.
- Gravel weights used (lb per cubic yard): Crushed stone (#57, clean) 2700; Crusher run / road base 3000; Pea gravel 2600; River rock 2600; Sand (dry) 2700; Topsoil 2200.
- Deck board spans (IRC 2021 Table R507.7): 5/4 wood (1 1/4 in) 16 in on center (12 in diagonal); 2x wood (2 in) 24 in on center (24 in diagonal).
- Stairs (IRC R311.7): riser max 7.75 in; tread min 10 in; variation max 0.375 in; headroom min 6 ft 8 in; width min 36 in.
- Roofing: 1 square = 100 sq ft; 3 bundles per square for most shingles; pitch multiplier = sqrt(1 + (rise/12)^2); waste 10% gable, 15% hip.
- Mulch: cubic yards = sq ft x depth (in) / 12 / 27; 13.5 bags of 2 cu ft or 9 bags of 3 cu ft per cubic yard; depth 2-4 in (Iowa State Extension), 6 in clear of trunks.
- Fence: posts = sections + 1 + one per gate; 3 rails per section above 4 ft; 1x6 pickets (5.5 in) at no gap = about 17.5 per 8 ft section.
- Brick (BIA Technical Note 10, 3/8 in joints): Modular brick (7 5/8 × 2 1/4 in) 6.75/sq ft; Queen brick 5.5/sq ft; King brick 4.55/sq ft; Utility brick 3/sq ft; Concrete block (8 × 8 × 16 in) 1.125/sq ft. 80 lb Mason Mix lays up to 37 bricks or 13 blocks.
- Wallpaper: count strips; strip = wall height + 4 in rounded up to the pattern repeat; US double roll typically 20.5 in x 33 ft.
- Carpet: bought in full roll-width drops (usually 12 ft wide) + 3 in trim per end; 1 sq yd = 9 sq ft.

## About

- [Methodology](https://materialguides.com/methodology/): every formula, constant and rounding rule.
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