River rock calculator

A 10 ft by 10 ft area covered 2 inches deep needs 0.62 cubic yards of river rock, about 0.82 tons at 2,650 lb per cubic yard. The calculator uses 2,650 lb per cubic yard (Pro Green Services).

Shape of the area
ft
ft
in
Result
0.82 tons

A 10 ft by 10 ft area covered 2 inches deep needs 0.62 cubic yards of river rock, about 0.82 tons at 2,650 lb per cubic yard.

Cubic yards
0.62
Cubic feet
16.7
Tons
0.82
Pounds
1,636
Tons at the published range, same condition
0.75–0.83
Rounded up to the next half yard
1 yd³

How it is calculated

  1. Area = 10 ft × 10 ft = 100 sq ft.
  2. Volume = 100 sq ft × 2 in ÷ 12 = 16.67 cu ft.
  3. Cubic yards = 16.67 ÷ 27 = 0.617 yd³.
  4. Weight = 0.617 yd³ × 2,650 lb/yd³ = 1,636 lb; ÷ 2,000 lb per ton = 0.82 tons.
TOP VIEWSECTION10 ft10 ft2 inRiver rockground

How to calculate river rock in cubic yards and tons

The worked numbers use the calculator's defaults: a 10 ft by 10 ft area 2 inches deep, the calculator's default depth for river rock.

Step 1: area in square feet

Rectangle: length × width

Circle: π × diameter² ÷ 4

Triangle: base × height ÷ 2

Example 10 ft × 10 ft = 100 sq ft

Split an irregular area into rectangles, circles and triangles and add their areas.

Step 2: cubic feet from area and depth

Cubic feet = area in sq ft × depth in inches ÷ 12

Example 100 × 2 ÷ 12 = 16.67 cu ft

Step 3: cubic yards from cubic feet

Cubic yards = cubic feet ÷ 27

Example 16.67 ÷ 27 = 0.617 cubic yards

Step 4: tons from cubic yards

Tons = cubic yards × pounds per cubic yard ÷ 2,000

Example River rock at 2,650 lb per cubic yard (Pro Green Services): 0.617 × 2,650 ÷ 2,000 = 0.82 tons

River rock for common areas

River rock for areas of 50 to 1,000 sq ft at the published depths: cubic yards and tons at 2,650 lb per cubic yard
Area, sq ft1 inch deep2 inches deep
500.15 yd³ · 0.2 t0.31 yd³ · 0.41 t
1000.31 yd³ · 0.41 t0.62 yd³ · 0.82 t
2000.62 yd³ · 0.82 t1.23 yd³ · 1.64 t
5001.54 yd³ · 2.04 t3.09 yd³ · 4.09 t
1,0003.09 yd³ · 4.09 t6.17 yd³ · 8.18 t

How much does a yard of river rock cover?

One cubic yard of river rock covers 162 sq ft at 2 inches deep; one ton at 2,650 lb per cubic yard covers 122 sq ft at the same depth.

Square feet one cubic yard and one ton (at 2,650 lb per cubic yard) of river rock covers by depth
Depth, in1 cubic yard covers, sq ft1 ton covers, sq ft
1324245
2162122
310882
48161
010020030040001234Area covered, sq ftDepth, in12341 cubic yard1 ton
  • 1 cubic yard
  • 1 ton
Area one cubic yard and one ton of river rock covers by depth.

Recommended river rock depth by use

Published depths for river rock run from 1 inch to 2 inches, depending on the use; each row names its document.

River rock depths as published, with the area one cubic yard covers at that depth
UseDepth, in1 cubic yard covers, sq ftSource
Garden gravel path (river run, round pieces), practical minimum2162University of California Agriculture and Natural Resources, Contra Costa Master Gardeners
Landscape mulch layer (gravel, pebbles, stones)1324Mississippi State University Extension

River rock weight per cubic yard

A cubic yard of river rock weighs about 2,650 lb (1.32 tons) (Pro Green Services). One ton of river rock is about 0.75 cubic yards.

Weight of river rock used by the calculator, its document row and condition, with the ranges of published values
Pounds per cubic yard2,650
Published as“River Rock (all)”, 1.325 ton/yd³, Pro Green Services; condition: not stated.
Published range, same condition, lb2,430–2,700
Tons per cubic yard1.33
Cubic yards per ton0.75

Every published value with its source, and tables of weight by volume and yards by tons: River rock weight.

River rock compared with other gravel and stone

Weight of a cubic yard as published, its condition (loose, compacted or not stated) and cubic yards per ton of the gravel and stone on this site, heaviest first; weights in different conditions are not comparable
MaterialConditionPounds per cubic yardCubic yards per ton
Crusher runcompacted3,7700.53
Pea gravelnot stated2,8400.7
Sandloose2,7950.72
River rocknot stated2,6500.75
Rockloose2,5700.78
Gravelloose2,5650.78
02,0004,000Weight, lb per cubic yardMaterialCrusher runCrusher run, Pounds per cubic yard: 3,7703,770Pea gravelPea gravel, Pounds per cubic yard: 2,8402,840SandSand, Pounds per cubic yard: 2,7952,795River rockRiver rock, Pounds per cubic yard: 2,6502,650RockRock, Pounds per cubic yard: 2,5702,570GravelGravel, Pounds per cubic yard: 2,5652,565
Weight of a cubic yard of the gravel and stone on this site.

River rock questions

How much river rock do I need?

A 10 ft by 10 ft area covered 2 inches deep needs 0.62 cubic yards of river rock, about 0.82 tons at 2,650 lb per cubic yard. One cubic yard of river rock covers 162 sq ft at 2 inches deep, so divide the area in square feet by 162 for the cubic yards at that depth.

Why the river rock you need can differ from the result

The weight of river rock changes with the source, the moisture and how tightly it is packed, so published values differ (here from 2,430 to 2,700 lb per cubic yard across all conditions). Before ordering, ask the supplier for the weight per yard of their own material and enter it as your own density under More options.

No document gives a compacted weight or a compaction factor for river rock: a compacted layer takes more than the tons shown, so ask the supplier.

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