Home Math & Calculator Tools Gravel Calculator
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Math & Calculator Tools

Gravel Calculator

Calculate how much gravel, crushed stone or pea gravel you need for your project — get cubic yards, cubic metres, tonnes and cost estimate.

⚡ Instant calculation 🔒 Private — runs in your browser 🚫 No login required 📋 Copy or download results
🪨 Gravel Calculator
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Enter your figures and click Calculate to see your results.

📖How to Use the Gravel Calculator

  1. 1
    Enter your values

    Enter the area length, width and desired depth, then optionally add a price per cubic yard to get a cost estimate.

  2. 2
    Click Calculate

    Press the Calculate button. All results appear instantly — no page reload, no waiting.

  3. 3
    Read and use your results

    Results appear in the panel on the right with all key values clearly labelled. Use Copy to grab the result or Download to save a text file.

💡When to Use This Calculator

SituationWhy It Helps
Driveway installation Get the right tonnage
Drainage projects Calculate aggregate depth
Landscaping & paths Plan material quantities

Frequently Asked Questions

How do I calculate how much gravel I need?

Multiply length (ft) × width (ft) × depth (ft) to get cubic feet, then divide by 27 to get cubic yards. For a 20 ft × 15 ft area at 4 inches (0.333 ft) deep: (20 × 15 × 0.333) / 27 = 3.7 cubic yards. Add 10% for settling and waste. One cubic yard of gravel weighs approximately 1.5 tonnes depending on stone type.

How deep should I lay gravel for a driveway?

A residential gravel driveway typically needs 4–6 inches of base gravel (crushed stone, Class 5 or road base) compacted, plus 2–3 inches of surface gravel (pea gravel or river rock) for a total of 6–9 inches. For heavy vehicle traffic, 8–12 inches of compacted base is recommended. Always compact each layer before adding the next.

What type of gravel is best for a driveway?

Crushed stone (3/4 inch) is the most popular driveway base — it compacts firmly and allows drainage. Pea gravel (3/8 inch, round) works as a surface layer but can shift. Road base or crusher run contains mixed sizes and fines that bind together well. Avoid large decorative river rocks on driveways — they shift under vehicle weight.

How much does a cubic yard of gravel weigh?

A cubic yard of gravel typically weighs 1.2–1.5 tons (1,100–1,350 kg) depending on stone type and moisture content. Dry pea gravel: ~1.25 tons/yd³. Crushed limestone: ~1.35 tons/yd³. River rock: ~1.4 tons/yd³. Wet gravel is heavier. Most bulk delivery trucks carry 8–15 cubic yards per load.

How thick should gravel be for a garden path?

A garden path needs 2–3 inches of gravel after compaction. The process: excavate 4–6 inches, add a layer of landscaping fabric, add 1–2 inches of coarse base material, then 2 inches of decorative gravel. Without a weed barrier and solid edge restraints, gravel migrates into lawn and garden beds over time.

What is the difference between gravel, crushed stone and pea gravel?

Gravel refers to naturally rounded stones formed by water erosion. Crushed stone is mechanically broken rock with angular edges that interlock and compact better. Pea gravel is small (3/8 inch), smooth rounded stones used for decorative purposes and drainage. Angular crushed stone is better for driveways; pea gravel is better for drainage and walkways.

How do I stop gravel from spreading or sinking?

Use edge restraints (plastic landscape edging, concrete borders, or timber) to contain gravel laterally. Place landscaping fabric beneath to prevent sinking into soil. Use a plate compactor to compact base layers. Choose angular crushed stone rather than round river rock — the angular edges lock together. Regular raking and top-dressing maintain surface level.

How often does a gravel driveway need replenishing?

A gravel driveway typically needs replenishing (top-dressing) every 3–5 years, adding 2–3 inches of new material. Annual raking redistributes migrated gravel. Ruts and potholes can be filled immediately. Installing the driveway correctly with proper compacted base layers dramatically reduces ongoing maintenance requirements.

How much does gravel cost?

Bulk gravel costs $15–$75 per cubic yard or $10–$50 per ton depending on stone type, region and quantity. Pea gravel is typically $35–$55/yd³. Crushed limestone: $20–$40/yd³. Decorative river rock: $50–$100/yd³. Delivery adds $50–$150 per load. Bagged gravel from hardware stores costs significantly more per cubic yard.

Do I need a base layer under gravel?

For driveways and high-traffic areas, yes — a compacted sub-base of crushed stone or road base is essential before adding surface gravel. Start with 4–6 inches of 3/4-inch crushed stone, compact with a plate compactor, then add 2–3 inches of surface material. For decorative garden paths with low traffic, a weed barrier and direct placement on firm soil is acceptable.