All mediums and aggregates are local: Although various norming standards for mediums have been defined (ASTM, US DOT, DIN, ANSI, etc.), those norm/standards are only rough averages: they are specific definitions of terms used in contract specifications sheets, architectural or engineering detail sheets, geotechnical designs, and so forth.

Real life stone, gravel and sand densities (weight / volume) vary widely: The local quarry or supplier which you elect to use should be able to provide the densities (tons / cubic yard) of their unique gravel, which they are quoting to you.
The densities of local mediums (gravels, crushed stone, aggregates, sands, etc) will vary from one quarry to the next.
The densities (pounds per square foot, or tons per cubic yard, sometimes called "pounds per foot" or "tons per cube") will also vary according to the season, the saturation levels (dampness) of the piles of medium when you purchase the mediums, the quality of the sieves used to sort the crusher runs, and so forth.

To  use the below chart in calculating how many tons your job requires:
Determine what type of local gravel or medium you will be using.
To convert tonnages into volumes (from tons to cubes) of gravel, sand, or other mediums into cubic yards ("cubes" or yd.³ per ):
Find the best description of the medium you are using - in the first column.
Copy the factor in the column titled "yards/ton" - a seven-decimal number in BLUE.
Multiply:
(your tonnage) x (yards/ton) = your cubic yards
(your metric tonnage) x (/tonne) = your cubic meters

To convert volumes into tonnages (from cubic yards into tons) of gravel, sand or other typical mediums into tons ("tons" or "Short Tons" - avdp):
Find the best description of the medium you are using - in the first column.
Copy the factor in the column titled "tons/yard" - a four-decimal number in RED.
Multiply:
(your cubic yards) x (tons / yard) = your US tons
(your cubic meters) x (tonnes / m³) = your metric tonnes

Below is a chart (it cannot execute any math, it's just a web page).


{source = www.ecoterr.com/media/xls/CHART-COMPLETE_tools_weights_calculators_convertor.xls; download filesize = 62 KB}

Generic "Gravel" *
(generic "common gravel")
Specific Gravity *
"pounds/foot"
(lb. / ft³) *
"tons/yard"
(t. / yd³)
"yards/ton"
(yd³ / t.)
Please note: That your gravel is NOT "common" - rather it is specific to your local supplier. Local gravels are all slightly different and unique to their source.
Below: Loosely defined "gravel" is based upon median specific gravities of typical minerals found in the USA which makeup your local "gravel."
Gravel, loose, dry
1.52
95
1.2825
0.7797271
Gravel, w/sand, natural
1.92
120
1.6200
0.6172839
Gravel, dry 1/4 to 2 inch
1.68
105
1.4175
0.7054674
Gravel, wet 1/4 to 2 inch
2.00
125
1.6875
0.5925926
Typical Weights of various typical minerals found in the USA:  *

QuickJump to » Clay | Earth | Granite | Limestone | Quartz | Sand | Shale | Slate | TOP of Page

Mineral Type (Material) *
Specific Gravity *
"pounds/foot"
(lb. / ft³) *
"tons/yard"
(t. / yd³)
"yards/ton"
(yd³ / t.)
Basalt, broken
1.96
122
1.6470
0.6071645
Basalt, solid
3.01
188
2.5380
0.3940110
Cement, Portland
3.15
94
1.2690
0.7880221
Cement, mortar
2.16
135
1.8225
0.5486968
 Below "clay" loosely defined ...
Clay, dry excavated
1.09
68
0.9180
1.0893246
Clay, wet excavated
1.83
114
1.5390
0.6497726
Clay, dry lump
1.07
67
0.9045
1.1055832
Clay, fire
1.36
85
1.1475
0.8714597
Clay, wet lump
1.60
100
1.3500
0.7407407
Clay, compacted
1.75
109
1.4715
0.6795789
 Below "earth" loosely defined ...
Earth, loam, dry, excavated
1.25
78
1.0530
0.9496676
Earth, moist, excavated
1.44
90
1.2150
0.8230453
Earth, wet, excavated
1.60
100
1.3500
0.7407407
Earth, dense
2.00
125
1.6875
0.5925926
Earth, soft loose mud
1.73
108
1.4580
0.6858711
Earth, packed
1.52
95
1.2825
0.7797271
Feldspar, solid
2.56
160
2.1600
0.4629630
Feldspar, pulverized
1.23
77
1.0395
0.9620010
 Granite, solid
2.69
168
2.2680
0.4409171
Granite, broken
1.65
103
1.3905
0.7191658
Gypsum, solid
2.79
174
2.3490
0.4257131
Gypsum, broken
1.81
113
1.5255
0.6555228
Gypsum, crushed
1.60
100
1.3500
0.7407407
Gypsum, pulverized
1.12
70
0.9450
1.0582011
Below "Limestone" varies widely across regions, depending upon local geology.
Calcium Carbonate (aka "Limestone" or CaCO3) in some areas is very soft and light, almost soapstone.
In some areas limestone is heavier + harder than granite (i.e. Bedford, Indiana limestone).
In some areas a very immature form of Limestone deposits is called "Caliche."
The below densities are based upon the average-median; or "a typical limestone which one might expect to find in many areas across the USA."
Definition of "limestone":  n. A colorless or white crystalline compound, CaCO3, occurring naturally as chalk, limestone, marble, Caliche, and other forms; "Limestone" is also used in a wide variety of manufactured products including commercial chalk, medicines, and dentifrices.
 Limestone, solid
2.61
163
2.2005
0.4544422
Limestone, broken
1.55
97
1.3095
0.7636502
Limestone, pulverized
1.39
87
1.1745
0.8514261
* Caliche (immature limestone)
1.44
90
1.2150
0.8230453
Mica, solid
2.88
180
2.4300
0.4115226
Mica, broken
1.60
100
1.3500
0.7407407
 Quartz, solid
2.64
165
2.2275
0.4489338
Quartz, lump
1.55
97
1.3095
0.7636502
Quartz sand
1.20
75
1.0125
0.9876543
Above: About Quartz, aka "Silica Dioxide" or SiO2...
Silica is the second most common element in the earth, following only oxygen (Silica comprises roughly 35% of the entire earth's mass, by most scientific estimates).
Common Quartz is also the fourth hardest natural mineral in the earth, following only: Diamonds, Sapphires and Topaz.
Because Quartz Sand is nonporous - and because it is an extremely adamant mineral - Quartz will not decay into dust or dissolve and wash away: as will all other typical minerals or sands.
This is why the beaches of the world are almost uniquely Quartz sand: all the other types of sand have long ago decayed into microscopic particles (colloidals) and dissolved away.
Rip-Rap (generic, non-specific)
1.60
100
1.3500
0.7407407
 Below "sand" loosely defined...
Sand, wet
1.92
120
1.6200
0.6172840
Sand, wet, packed
2.08
130
1.7550
0.5698006
Sand, dry
1.60
100
1.3500
0.7407407
Sand, loose
1.44
90
1.2150
0.8230453
Sand, rammed
1.68
105
1.4175
0.7054674
Sand, water filled
1.92
120
1.6200
0.6172840
Sand w/ Gravel, dry
1.73
108
1.4580
0.6858711
Sand w/ Gravel, wet
2.00
125
1.6875
0.5925926
Sandstone, solid
2.32
145
1.9575
0.5108557
Sandstone, broken
1.51
94
1.2690
0.7880221
 Shale, solid
2.68
167
2.2545
0.4435573
Shale, broken
1.59
99
1.3365
0.7482230
 Slate, solid
2.69
168
2.2680
0.4409171
Slate, broken
1.67
104
1.4040
0.7122507
Slate, pulverized
1.36
85
1.1475
0.8714597

QuickJump to » Clay | Earth | Granite | Limestone | Quartz | Sand | Shale | Slate | TOP of Page
* Authority cited for typical mineral weights:
Reade at www.reade.com/Particle_Briefings/spec_gra2.html

Determine how many Cubic Yards your job requires, based upon dimensions:
(feet wide) x (feet long) x (inches deep) = cubic yards required
Convert Lengths and Distances to and from metric, British units {feet, yards, miles, etc.}, scientific units, archaic units (roods, Rods, etc). astronomical units of measure, and so forth.
Convert Areas to and from metric, British units {acres, townships, square miles, square feet, etc.}, scientific units, archaic units, international units, and so forth.
Convert Masses or Weights to and from metric units, British units {acres, townships, square miles, square feet, etc.}, scientific or nuclear-subatomic weights, archaic units, international units, and so forth.