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

Washed stone with the fines removed, sold as 3/4 clean, 3/4 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:

• #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 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.