How much material do you need?

Every project starts with the same question, and the answer is almost never on the bag. Pick a calculator, put in your measurements, and get the amount in the units you buy in — cubic yards, tons, or bags.

Mulch CalculatorAs a rule of thumb, one cubic yard of mulch covers about 162 sq ft at 2 inches deep, which is roughly 8 bags of 2 cu ft mulch per 100 sq ft.Gravel CalculatorOne cubic yard of gravel weighs roughly 1.4 US tons (about 2,800 lb), and covers about 162 sq ft at 2 inches deep or 81 sq ft at 4 inches deep.Concrete CalculatorA 10 ft × 10 ft slab at 4 inches thick needs about 1.23 cubic yards of concrete — that is roughly 56 bags of 80 lb mix if you are mixing it yourself.Paint CalculatorOne gallon of paint covers about 350 sq ft per coat. A typical 10 ft × 12 ft bedroom with an 8 ft ceiling needs about 2 gallons for two coats.

Why these calculators exist

Ordering material is where home projects go wrong. Order too little and you make a second trip, or end up with a visible cold joint in a concrete pour. Order too much and you are paying for a pile of gravel that sits in the driveway for a year.

Each calculator on this site takes your measurements and converts them into the units your supplier actually sells. Where a material is normally bought by weight or by the bag, both numbers are shown.

How to use them

Measure the area. Length times width in feet. For a room, use the wall perimeter instead.
Choose a depth. Each calculator lists the usual depth for that material and job.
Read the result. You get the volume, plus bags or tons where that is how it is sold.
Add a little. Five to ten percent extra covers waste, settling and uneven ground.

All results are estimates for planning. Product specs vary, so confirm the final quantity with your supplier. Last updated 2026-09-30.