Building material calculator
How much do you actually need? Enter your dimensions and get a quantity you can take to the counter: yards and bags of concrete, blocks and mortar, tiles and grout, drywall sheets and buckets of mud, fence posts, bundles of shingles, tons of gravel, yards of mulch. Imperial units, no sign-up, no form to fill in.
- Every formula written out on the page, step by step
- Coverage rates cited to the manufacturer that publishes them
- Waste allowances you can change, because your job site is not average
- Opens fast on a phone with one bar of signal
Pick a calculator
- Concrete Calculator Cubic yards and bags for a slab, a footing, a round column or a flight of steps, with the allowance applied. Slabs and footings
- Concrete Slab Calculator Yards and bags of every size for a 10x10 pad, a driveway or a patio, and the ready-mix order. Slabs
- Concrete Bags per Yard How many 40, 50, 60 and 80 lb bags make a cubic yard, with a converter for any volume. Bagged concrete
- Concrete Block Calculator 8x8x16 blocks for a wall, the bags of mortar mix to lay them and the grout to fill the cells. Masonry
- Tile Calculator Tile count with a cutting allowance, boxes to buy, thin-set by trowel size and grout by the pound. Floors and walls
- Drywall Calculator Sheets for 4x8, 4x10 and 4x12 panels with doors and windows deducted, plus screws, mud and tape. Walls and ceilings
- Fence Calculator Posts, rails and pickets from your run length, plus the bags of concrete each post hole takes. Outdoor
- Roofing Calculator Squares and shingle bundles from your footprint and roof pitch, plus underlayment and ridge cap. Outdoor
- Gravel Calculator Cubic yards and tons of stone for paths and paver base, with a compaction allowance and your density. Outdoor
- Gravel Driveway Calculator Base, middle and surface stone for a driveway, each layer in cubic yards and tons. Outdoor
- Mulch Calculator Cubic yards and bags for beds and tree rings at the depth you choose, bags versus bulk explained. Garden
Which material calculator do I need?
- Pouring a patio, a shed pad or a driveway slab: the concrete slab calculator.
- Footings, piers, post holes or steps: the concrete calculator.
- You know the cubic yards and need the bag count: concrete bags per yard.
- A block wall, a foundation wall or a retaining wall: the concrete block calculator.
- Floor, wall or backsplash tile: the tile calculator.
- Hanging or finishing drywall: the drywall calculator.
- A new wood fence: the fence calculator.
- Reroofing with asphalt shingles: the roofing calculator.
- A gravel path, a patio base or one layer of stone: the gravel calculator.
- A new gravel driveway built in layers: the gravel driveway calculator.
- Garden beds and tree rings: the mulch calculator.
Concrete calculator: cubic yards and bags
The concrete calculator works out slabs, continuous footings, round columns and steps, then converts the volume into cubic yards and bags with your waste allowance. A 10 x 10 ft slab 4 in thick is 1.23 cubic yards, or 62 bags of 80 lb mix with 10 % extra.
Concrete slab calculator
The concrete slab calculator starts from a 10x10 pad, a driveway or a patio and shows every bag size side by side with the ready-mix order. A 12 x 24 ft driveway 4 in thick takes 3.91 cubic yards with waste, which is 176 bags of 80 lb or a 4 yard truck.
Concrete bags per yard
Concrete bags per yard converts any volume into bags, using the yields printed on the manufacturer data sheet. One cubic yard is 45 bags of 80 lb, 60 bags of 60 lb, 72 bags of 50 lb or 90 bags of 40 lb.
Concrete block calculator
The concrete block calculator counts 8x8x16 blocks at 1.125 per square foot of wall, then the mortar mix and the grout for the cells. A wall 20 ft long and 6 ft high takes 135 blocks, 142 with 5 % extra, and 11 bags of 80 lb mortar mix.
Tile calculator
The tile calculator divides the floor or wall area by the area of one tile, adds a cutting allowance, then counts boxes, thin-set and grout. A 12 x 10 ft floor in 12x12 tile is 120 tiles, or 132 with 10 % extra.
Drywall calculator
The drywall calculator takes room dimensions, deducts doors and windows, and returns sheets, screws, joint compound and tape. A 12 x 12 ft room with 8 ft walls and a ceiling is 528 sq ft, or 19 sheets of 4x8 with 10 % waste.
Fence calculator
The fence calculator turns a run length and a post spacing into posts, rails, pickets and the concrete for every hole. A 100 ft fence takes 14 posts at 8 ft spacing, or 18 at 6 ft.
Roofing calculator
The roofing calculator applies the pitch multiplier to your footprint and counts squares, bundles, underlayment and ridge cap. A 2,000 sq ft roof is 20 squares, or 60 bundles, before 10 % to 15 % waste.
Gravel calculator
The gravel calculator converts an area and a depth into cubic yards and tons, with a compaction allowance and a density you can set. A 20 x 10 ft area 4 in deep takes 2.96 cubic yards, about 4.15 tons.
Gravel driveway calculator
The gravel driveway calculator works out base, middle and surface stone in one pass, each with its own depth and density. A 12 x 50 ft driveway in layers of 4, 3 and 2 in takes 20 cubic yards, or about 28 tons.
Mulch calculator
The mulch calculator gives cubic yards and bags for beds and tree rings at the depth you choose. A 20 x 10 ft bed at 3 in takes 1.85 cubic yards, or 25 bags of 2 cu ft.
From the blog
Measure before you calculate
A material calculator is only as good as the tape measure behind it. Measure each dimension twice, write it down in feet and inches, and split odd shapes into rectangles and circles you can add back together. Depths and thicknesses are the numbers people guess most often and the ones that move the result the most: one extra inch on a 4 in slab adds a quarter to the concrete, and one extra inch of gravel on a driveway adds a quarter to the tonnage. Use a straightedge and a ruler at several points rather than a single reading, and take the average.
Then check the product you will actually buy. Bag yields, tile sizes, box counts and bundle coverage are printed on the label, and they win over any default on this site.
What we assume, on every page
- Quantities round up, always. Materials are sold in whole tiles, whole sheets and whole bags.
- Waste is a real cost, not padding. The default allowance is 10 % for straightforward work and 15 % where every perimeter piece is cut twice. Both are editable.
- Coverage rates come from manufacturers. Each one is named and linked. Where a rate varies by product, the page says so and tells you to read your bag.
- The result is an estimate. A calculator has never seen your substrate, your frost line or your framing. Confirm before ordering.
There is no form anywhere on this site. We do not ask for your name, your email, your phone number or your address, and we do not sell leads to contractors. Some links to suppliers earn a commission if you buy through them, which is stated on the page where the link appears.
Quick reference: the conversions everything depends on
| Conversion | Value | Where it shows up |
|---|---|---|
| Cubic feet in a cubic yard | 27 | Anything sold by the yard |
| Square inches in a square foot | 144 | Tile, grout |
| Inches in a foot | 12 | Thickness, depth |
| Yield of an 80 lb bag of concrete mix | 0.6 cu ft | Post holes, footings |
| Yield of a 60 lb bag of concrete mix | 0.45 cu ft | Post holes, footings |
| Area of a 4 ft x 8 ft drywall sheet | 32 sq ft | Walls, ceilings |
| Concrete blocks per square foot of wall | 1.125 | Block walls |
The single most common estimating error in residential work is forgetting that thickness is in inches while length and width are in feet. Divide the inches by 12 before you multiply, every time.