3/4 Gravel Calculator

What Is 3/4 Gravel?

3/4 gravel is stone that has been screened so most pieces are about three quarters of an inch across — roughly the size of a grape. The name covers two quite different products, and the 3/4 gravel calculator needs to know which one you are buying because they behave and weigh differently.

Clean 3/4 gravel (3/4 clean stone)

Washed stone with the fines removed, sold as 3/4 clean stone, 3/4 inch crushed stone or #57 stone. The open voids let water pass straight through, so it is the standard 3/4 gravel for French drains, behind retaining walls, under concrete and as a driveway top layer. It does not compact into a solid surface.

3/4 minus gravel

The same 3/4 inch stone with all the smaller pieces and stone dust left in — the “minus”. The fines fill the gaps and lock everything together under a compactor, which makes 3/4 minus the right 3/4 gravel for a driveway base, a shed pad or a paver base. It is heavier at about 1.50 tons per cubic yard.

3/4 Gravel Weight

A cubic yard of 3/4 gravel weighs between 1.35 and 1.50 tons depending on the stone and the fines content. These are the loose, dry figures the calculator uses:

Wet stone can weigh 5 to 10 percent more. If you buy by the ton after heavy rain, you get slightly less volume than the 3/4 gravel calculator predicts, which is one more reason to keep a 10 percent allowance.

3/4 Gravel Coverage

One cubic yard of 3/4 gravel covers about 162 sq ft at 2 inches, 108 sq ft at 3 inches, 81 sq ft at 4 inches and 54 sq ft at 6 inches. One ton of 3/4 crushed stone covers roughly 116, 77, 58 and 39 sq ft at the same depths.

3/4 gravel depth

• Driveway top layer: 2 to 3 inches of clean 3/4 over a compacted 3/4 minus or crusher run base.
• Driveway base: 4 to 6 inches of 3/4 minus, compacted in 2 to 3 inch lifts.
• Under a concrete slab: 4 inches of 3/4 gravel, per most residential codes.
• French drain: fill the trench, usually 12 to 18 inches of clean 3/4 around the pipe.
• Walkway: 3 inches; 3/4 minus packs firmer underfoot than clean stone.

How the 3/4 Gravel Calculator Works

1. 3/4 gravel area

Multiply length by width in feet. A 20 × 10 ft parking pad is 200 sq ft.

2. 3/4 gravel volume

Multiply by the depth in feet and divide by 27. At 4 inches: 200 × 0.333 ÷ 27 = 2.47 cubic yards.

3. Tons of 3/4 gravel

Multiply by the density: 2.47 × 1.40 = 3.46 tons of 3/4 crushed stone, or 3.7 tons of 3/4 minus. Add 10 percent and order about 3.8 tons of clean stone.

4. Bags of 3/4 gravel

A 50 lb bag of 3/4 gravel holds about half a cubic foot. 3.8 tons is 7,600 lbs, or 152 bags — at that size bulk delivery is almost always cheaper.

3/4 Gravel vs #57 Gravel

#57 stone is the ASTM size number for clean crushed stone that ranges from about 1 inch down to 1/2 inch, so in practice most suppliers sell #57 and clean 3/4 gravel as the same product. Our #57 gravel calculator gives the same answer for clean stone. Smaller pea gravel at 3/8 inch is rounder and more comfortable underfoot but will not lock together. Larger 1-1/2 inch stone such as #4 is used for the bottom of deep driveway builds and for erosion control.

3/4 Gravel Price

3/4 gravel typically costs $28 to $45 per ton, or $40 to $65 per cubic yard, at the quarry. 3/4 minus is usually the cheapest; washed granite and river rock the most expensive. Bagged 3/4 gravel at a home center costs $4 to $7 per 50 lb bag, which works out to $160 to $280 per ton — four to six times the bulk price.

Related Gravel Calculators

These tools use the same volume and density maths for neighbouring jobs:

• Stone calculator — every stone type, not just 3/4
• #57 gravel calculator — the ASTM-sized equivalent of clean 3/4 stone
• Crusher run calculator — 3/4 minus style base with fines
• Crushed stone calculator — every crushed stone size
• Gravel under concrete slab calculator — the 4 inch base under a slab
• French drain calculator — trench volume and clean stone
• Gravel size chart — how gravel numbers map to inches

Density figures follow standard quarry ranges for crushed aggregate; the USGS crushed stone statistics publish national production and unit value data.

3/4 Gravel FAQ

How do I calculate 3/4 crushed stone?

Multiply length by width in feet, multiply by the depth in inches divided by 12, then divide by 27 for cubic yards. Multiply cubic yards by 1.40 for tons of 3/4 inch crushed stone and add about 10 percent. A 200 sq ft area 4 inches deep needs about 2.5 cubic yards, or 3.8 tons with waste.

How much does a yard of 3/4 gravel weigh?

A cubic yard of clean 3/4 gravel weighs about 1.35 to 1.40 tons, or 2,700 to 2,800 lbs. 3/4 minus with fines is heavier at about 1.50 tons per cubic yard because the fines fill the voids between stones.

How much area does a ton of 3/4 gravel cover?

One ton of 3/4 crushed stone covers about 116 sq ft at 2 inches deep, 77 sq ft at 3 inches, 58 sq ft at 4 inches and 39 sq ft at 6 inches.

Is 3/4 gravel the same as #57 stone?

Nearly. #57 is the ASTM size for clean crushed stone between about 1 inch and 1/2 inch, and most suppliers sell it as 3/4 gravel. 3/4 minus is different because it keeps the fines and stone dust.

Is 3/4 gravel good for a driveway?

Clean 3/4 gravel makes a good top layer 2 to 3 inches thick, but it stays loose on its own. Build the base from 4 to 6 inches of compacted 3/4 minus or crusher run, then top it with clean 3/4 stone.

How many bags of 3/4 gravel are in a ton?

About 40 bags of 50 lb, or 50 bags of 40 lb. Each 50 lb bag holds roughly half a cubic foot, so a cubic yard of 3/4 gravel is about 54 to 56 bags.