Gravel Calculator

Formula

Tons = (Length × Width × Depth in ft × lbs/cu ft) ÷ 2000

Calculate volume in cubic feet, multiply by weight per cubic foot (varies by gravel type), then divide by 2000 to convert pounds to tons.

Worked Examples

Example 1: Standard Driveway

Problem:Calculate gravel for a 50-foot long, 12-foot wide driveway with 4-inch gravel depth.

Solution:Area = 50 × 12 = 600 sq ft Volume = 600 × (4/12) = 200 cubic feet Cubic yards = 200 ÷ 27 = 7.4 yards Weight (crushed stone at 100 lb/cu ft): 200 × 100 = 20,000 lbs = 10 tons Cost at $30/ton: 10 × $30 = $300 + delivery

Result:7.4 cubic yards, 10 tons, ~$375 total

Example 2: Circular Patio Base

Problem:Calculate gravel for a 15-foot diameter circular patio base at 3 inches deep.

Solution:Radius = 15 ÷ 2 = 7.5 feet Area = π × 7.5² = 176.7 sq ft Volume = 176.7 × (3/12) = 44.2 cubic feet Cubic yards = 44.2 ÷ 27 = 1.64 yards Weight: 44.2 × 96 = 4,243 lbs = 2.1 tons Pea gravel at $35/ton: 2.1 × $35 = $74

Result:1.64 cubic yards, 2.1 tons, ~$150 with delivery

Example 3: French Drain

Problem:Calculate gravel for 60 linear feet of French drain, 12 inches wide and 18 inches deep.

Solution:Volume = 60 × 1 × 1.5 = 90 cubic feet Cubic yards = 90 ÷ 27 = 3.33 yards Weight (washed stone at 95 lb/cu ft): 90 × 95 = 8,550 lbs = 4.3 tons Drainage stone at $40/ton: 4.3 × $40 = $172 + delivery

Result:3.33 cubic yards, 4.3 tons, ~$250 total

Frequently Asked Questions

How deep should gravel be for a driveway?

Driveway gravel depth depends on layers: Sub-base (larger crushed stone): 4-6 inches. Base layer (medium crushed stone): 3-4 inches. Top layer (pea gravel or crusher fines): 2-3 inches. Total depth: 8-12 inches for best durability. Single-layer gravel driveways need 4-6 inches minimum. Add more depth for heavy vehicle traffic.

How much gravel do I need for a 10x20 area?

For a 10×20 ft area (200 sq ft) at 4 inches deep: Volume = 200 × (4/12) = 66.7 cubic feet = 2.47 cubic yards. Weight varies by type: about 3-4 tons for most gravel. At $35/ton for crushed stone, material costs about $100-140 plus delivery.

What type of gravel is best for driveways?

Best driveway options: Base layer: #3 crushed stone (1-2 inches) or quarry process. Middle layer: #57 stone (3/4-1 inch). Top layer: #8 or #9 stone (3/8-1/2 inch), or crusher run that packs well. Avoid round stones like pea gravel for driving surfaces - angular stones interlock better.

How do I calculate gravel in tons?

First calculate cubic feet (length × width × depth in feet). Multiply by weight per cubic foot (varies by type, typically 90-110 lbs). Divide by 2,000 to get tons. Example: 100 cu ft of crushed stone at 100 lbs/cu ft = 10,000 lbs = 5 tons. Always order 10% extra for settling and spreading.

Is it cheaper to buy gravel by the yard or ton?

Suppliers price differently, so compare both. One cubic yard weighs about 1.3-1.5 tons depending on type. If gravel is $40/yard or $30/ton, you need to convert: $40/yard ÷ 1.4 tons/yard = $28.57/ton - so the per-yard price is slightly cheaper in this case. Get quotes both ways.

How much area does a ton of gravel cover?

Coverage depends on depth: At 2 inches: ~100 sq ft per ton. At 3 inches: ~70 sq ft per ton. At 4 inches: ~50 sq ft per ton. At 6 inches: ~35 sq ft per ton. These are estimates - actual coverage varies by gravel type, shape, and how it's spread.

What's the difference between crushed stone and gravel?

Crushed stone is mechanically broken rock with angular edges - it interlocks and compacts well. Gravel refers to naturally rounded stones from rivers or beaches. Crushed stone is better for bases and driveways (compaction). Natural gravel is better for decorative uses (walks, gardens). 'Pea gravel' is small rounded stones.

Do I need landscape fabric under gravel?

Landscape fabric helps prevent weed growth and keeps gravel from sinking into soil. Recommended for: decorative gravel areas, garden paths, around plants. Not needed for: driveways with proper base layers, areas getting heavy traffic (compaction works better). Use heavyweight fabric rated for gravel, not thin weed barrier.

How do I edge a gravel area?

Edging keeps gravel contained and reduces migration. Options: Steel edging (professional, durable), plastic edging (affordable, flexible), brick/stone borders (decorative), pressure-treated timber (rustic), concrete curbing (permanent). Install edging before gravel. Set depth to match gravel surface level.

Will gravel compact over time?

Yes, gravel settles 10-20% after installation. Angular crushed stone compacts more than rounded gravel. Compact with a plate compactor or roller after spreading for stability. Water and traffic cause additional settling. Plan for periodic top-dressing to maintain level. Initial compaction reduces long-term settling.

Background & Theory

Gravel is one of the most versatile landscaping and construction materials. Understanding gravel types, calculations, and applications helps ensure successful projects for driveways, pathways, drainage, and decorative purposes. **Gravel Types by Size:** **Screenings/Fines (0-3/8"):** Compacts well, for base layers and filling gaps **Pea Gravel (3/8"):** Rounded, comfortable underfoot, decorative **#57 Stone (3/4-1"):** Common for drainage and driveways **#3 Stone (1-2"):** Larger base material, drainage **River Rock (1-3"):** Decorative, rounded **Riprap (6"+):** Erosion control, very large **Calculating Gravel Needs:** **Volume in Cubic Feet:** Volume = Length × Width × Depth (all in feet) **Volume in Cubic Yards:** Cubic Yards = Cubic Feet ÷ 27 **Weight in Tons:** Tons = (Cubic Feet × Lbs per Cu Ft) ÷ 2000 **Weight by Gravel Type (lbs/cu ft):** - Pea gravel: 90-100 - Crushed stone: 100-105 - River rock: 85-95 - Quarry process: 100-110 **Coverage Estimates per Ton:** - 2" depth: 100 sq ft - 3" depth: 70 sq ft - 4" depth: 50 sq ft - 6" depth: 35 sq ft **Depth Recommendations:** **Walkways:** 2-3 inches of decorative gravel **Patios:** 4 inches compacted base + 2 inches surface **Driveways:** 4-6 inches base + 2-3 inches surface **Drainage:** Varies by application, typically 12-18 inches **French Drains:** Fill around pipe completely **Cost Factors:** - Type of stone (decorative costs more) - Quantity (bulk is cheaper per ton) - Delivery distance - Delivery method (dump truck, stone slinger) - Local availability **Installation Tips:** 1. Mark area and remove vegetation/topsoil 2. Grade for drainage (slope away from structures) 3. Install edging to contain gravel 4. Lay landscape fabric if needed 5. Spread gravel in layers, compact each 6. Finish to desired depth 7. Expect 10-20% settling

History

Gravel has been used in construction and landscaping for thousands of years. Roman roads, famous for their durability, used multiple layers of gravel and stone in their construction. The Appian Way, built in 312 BC, still has visible sections today. The word "gravel" comes from Old French "gravele," diminutive of "grave" meaning seashore or sand. This reflects gravel's natural origins in riverbeds and beaches where water rounds stone fragments over millennia. Before modern pavement, gravel roads were the standard throughout the developed world. John McAdam developed "macadamized" roads in the early 1800s, using carefully graded crushed stone that compacted into a durable surface. This revolutionized transportation and remained standard until asphalt paving became widespread in the 20th century. Gravel mining became an industry in itself. Glacial deposits in northern regions provided abundant sources of naturally sorted stone. Quarrying operations developed crushing equipment to produce graded stone products from solid rock. Modern gravel production involves sophisticated crushing, screening, and washing operations. Different sizes and types serve specific purposes: from massive riprap for erosion control to fine screening for golf course bunkers. The industry produces billions of tons annually for construction, landscaping, and infrastructure. Today's decorative gravel market offers stones from around the world - Mexican beach pebbles, Scottish granite, Italian marble chips - alongside local crushed stone. The humble gravel driveway remains one of the most cost-effective surfacing options.