Decorative Rock Calculator
Estimate the cubic yards, tons and bags of decorative rock or river rock for beds and borders.
What you need
1.30cu yd
Decorative Rock needed — Order this much loose material, including your waste allowance.
- Same amount in cubic feet
- 35.0 cu ft
- Approximate weight
- 1.75 US tons
- Area you are covering
- 200.0 sq ft
- Bags needed
- 70
Useful for checking trailer, truck or wheelbarrow limits.
Rounded up — you can only buy whole bags.
Estimates for planning. Confirm quantities with your supplier before ordering — see the assumptions below for the figures used.
How to use the decorative rock calculator
Decorative rock is a one-time job that lasts for years — which makes getting the quantity right the first time worth a few minutes. Enter your bed dimensions and the depth of cover you want.
What this calculator assumes
Every estimate depends on figures that vary by supplier and conditions. These are the ones used here, so you can sanity-check the result against your own quote.
- Bulk density is assumed to be about 2,700 lb per cubic yard. Loose material varies with moisture and how finely it is ground, so treat the weight as an estimate.
- One cubic yard is 27 cubic feet. Suppliers almost always sell loose material by the cubic yard.
- Results include whatever waste allowance you entered. Bag counts are rounded up.
- River rock and decorative stone average about 2,700 lb per cubic yard.
- Cover depth should be roughly twice the stone diameter — any deeper is wasted material.
Frequently asked questions
How much river rock do I need per square foot?
At 2 inches deep, about 0.167 cubic feet per square foot — so one cubic yard covers roughly 162 square feet. In weight terms that is close to 17 pounds per square foot.
Does decorative rock stop weeds?
It slows them, but wind-blown seed germinates in the dust that collects between stones within a couple of years. Rock over landscape fabric works better, and unlike organic mulch you cannot simply top it up to bury the problem — you have to weed it.
Is rock or mulch better around a house?
Rock does not decompose, blow away or need annual replacement, and it will not hold moisture against siding. Mulch feeds the soil and keeps roots cooler. In hot climates, rock next to a wall radiates significant heat back at the building.
How do I measure my area for decorative rock?
Measure the length and width in feet at the widest points and multiply them. For an irregular bed, break it into rectangles, circles and triangles, calculate each one separately and add the results together. Rounding up slightly is safer than rounding down.
Should I order bulk or bags?
Bulk is almost always cheaper per cubic yard once you need more than about 1 cubic yard — roughly 54 bags. Bags win when you need a small amount, have nowhere to dump a pile, or want to spread the job over several weekends.
Will a cubic yard fit in my pickup truck?
A half-ton pickup can usually carry about 1 cubic yard of light material like mulch, but only around half a cubic yard of wet soil or gravel because of the weight. Check the weight figure above against your vehicle's payload rating before you load up.
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