How much material do you need?

Calculators

Weekend projects

Three common jobs, worked through. Open one to see every number with the math, then change the sizes to match your yard.

• Pea gravel patio

  10 × 12 ft, 3 in deep. With 5% extra, order 1.17 cu yd, or 63 bags of 0.5 cu ft.

  Open this example: pea gravel patio
• Raised garden bed

  4 × 8 ft, filled 12 in deep with garden soil: 32 cu ft once settled. Buy 40.3 cu ft, or 27 bags of 1.5 cu ft, to cover settling and 5% extra.

  Open this example: raised garden bed
• Fence post footings

  Ten holes, 10 in wide and 30 in deep. With 10% extra that’s 15 cu ft of concrete, or 25 80-lb bags. The posts take up some of each hole, so you’ll have a little left over. Check your local frost depth before you dig.

  Open this example: fence post footings

Guides and reference

• Bags of concrete per yard40, 50, 60 and 80 lb bags, and what each covers.
• Bags or ready-mix?When a truck makes more sense than mixing bags.
• Concrete slab thicknessPatios, walks, driveways and garage floors.
• Mulch depth guideHow deep by mulch type, and what to avoid.
• Pickup and dump truck capacityHow much fits, by volume and by weight.
• Material weightsEvery weight this site uses, with sources.
• Bag sizes and yieldsConcrete, gravel, sand, soil and mulch bags.

Where the numbers come from

Each calculator uses weights, yields and coverage from manufacturer data sheets, industry standards (such as CRI 105 for carpet), the International Residential Code, state transportation departments, university extension services and, where nothing better exists, retailer listings and suppliers (marked as secondary sources). Each page lists its sources. The shared formulas are checked against a table of hand-worked answers every time the site is built, and bag and truck counts are always rounded up.

When you have several jobs, add each result to your project list and print one sheet to take to the supply yard.