OmniCalc

Gravel Calculator

Construction

Calculate gravel volume for landscaping

Gravel suppliers quote prices two different ways — by the cubic yard for volume, or by the ton for weight — and homeowners are frequently caught off guard when a delivery truck asks how many tons to drop off, not how many yards. Since gravel is priced by weight but a project's need is really about filling a volume, converting correctly between the two is essential to ordering the right amount and avoiding a surprise bill.

Our gravel calculator solves both halves of this problem. Enter your project's length, width, and depth to get the cubic yard volume, then the calculator converts that volume into an estimated tonnage using gravel's typical density, so you have the exact numbers a supplier needs whether they quote by volume or by weight.

This works for driveways, walkways, drainage beds, and gravel base layers under patios or sheds — just adjust the depth to match your specific project's requirements.

Why Gravel Calculator Matters

Gravel delivery is priced by the ton, and most suppliers have delivery minimums, so an inaccurate estimate can mean paying for a partially wasted truckload or having to schedule and pay for a second delivery to finish the job. Because gravel's density varies noticeably by material type — crushed stone, pea gravel, and river rock all pack differently — using a generic weight estimate without adjusting for your specific material can throw off your tonnage by 10% or more.

Getting the depth right matters just as much as getting the footprint right. A gravel driveway typically needs 4–6 inches of depth to properly bear vehicle weight and resist rutting, while a decorative walkway or drainage bed might only need 2–3 inches. Ordering based on the wrong depth assumption — either too shallow, which leads to a driveway that ruts and requires regrading within a year, or too deep, which wastes material and budget — is one of the most common and costly gravel-project mistakes homeowners make.

The Gravel Calculator Formula, Explained

Volume (cubic yards) = Length (ft) × Width (ft) × Depth (ft) / 27; Weight (tons) = Volume (cubic yards) × 1.4

Calculate volume the same way as concrete: multiply length × width × depth (all in feet) to get cubic feet, then divide by 27 to convert to cubic yards, since one cubic yard equals 27 cubic feet.

To convert volume into weight, multiply cubic yards by gravel's average density, roughly 1.4 tons per cubic yard for standard crushed stone or gravel mixes. This figure varies by material — pea gravel runs slightly lighter at around 1.3–1.35 tons per cubic yard, while denser crushed stone or road base can run closer to 1.4–1.5 tons per cubic yard — so check with your specific supplier for their material's exact density if precision matters for your budget.

Most suppliers deliver and price by the ton rather than the cubic yard, so the tonnage figure is typically what you'll use to place your actual order. As with concrete, it's wise to round your final order slightly upward, since running short mid-project on a delivered bulk material means scheduling and paying for an entirely separate delivery.

How to Use the Gravel Calculator: Step by Step

  1. Measure length and width

    Measure the length and width of the area to be covered with gravel, such as a driveway or walkway, in feet.

  2. Determine the required depth

    Choose the appropriate depth for your project — typically 4–6 inches for a driveway, 2–3 inches for a walkway or decorative bed, or per manufacturer specs for a drainage or paver base layer.

  3. Calculate cubic yards

    Multiply length × width × depth (all in feet) to get cubic feet, then divide by 27 to convert to cubic yards.

  4. Convert to tons for ordering

    Multiply the cubic yard volume by your gravel material's density (about 1.4 tons per cubic yard as a general average) to get the tonnage figure most suppliers use for pricing and delivery.

Gravel Calculator Examples: Real-World Scenarios

1

Gravel Driveway

A homeowner is covering a 50 ft × 10 ft driveway with crushed stone at a 6-inch depth to properly support vehicle weight.

Length:50 ft
Width:10 ft
Depth:6 in (0.5 ft)
Density:1.4 tons/cu yd

Calculation

Volume = 50 × 10 × 0.5 / 27 = 250 / 27 = 9.26 cubic yards; Weight = 9.26 × 1.4 = 12.96 tons

Result

Order approximately 13 tons of crushed stone from the supplier, which is the figure to give when scheduling delivery.

2

Garden Walkway

A homeowner is filling a 3 ft × 20 ft garden walkway with pea gravel at a shallower 3-inch depth, using pea gravel's slightly lower density.

Length:3 ft
Width:20 ft
Depth:3 in (0.25 ft)
Density:1.35 tons/cu yd (pea gravel)

Calculation

Volume = 3 × 20 × 0.25 / 27 = 15 / 27 = 0.556 cubic yards; Weight = 0.556 × 1.35 = 0.75 tons

Result

Order 1 ton of pea gravel, since most suppliers have a 1-ton minimum delivery, which comfortably covers this small walkway with a bit of surplus.

Common Mistakes to Avoid

  • Using a single generic density figure for every gravel type, when pea gravel, crushed stone, and river rock all pack at slightly different weights per cubic yard — ask your supplier for the specific material's density for a more accurate order.
  • Choosing too shallow a depth for a driveway — under 4 inches of gravel typically cannot support regular vehicle traffic without rutting and will need to be topped up or regraded within a year.
  • Forgetting that gravel compacts after installation and settling, so a project may need a small top-up layer a few weeks after the initial spread, especially in high-traffic areas.

Tips & Tricks

  • Always confirm your supplier's delivery minimum in tons before finalizing your order — small projects under about 1 ton may face a minimum delivery charge regardless of the calculated tonnage.
  • For a driveway base, consider a two-layer approach: larger crushed stone at the bottom for drainage and stability, topped with a finer decorative gravel layer, and calculate each layer's volume and tonnage separately.

Converting between volume and weight correctly ensures you order the right amount of gravel and avoid both delivery shortfalls and wasted material costs. Use this calculator before your next delivery, and pair it with our concrete calculator if you're building a gravel base under a slab, or our lumber calculator for edging and forms.

Gravel Calculator — Frequently Asked Questions

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Authoritative References

NACHI — Drainage and Grading Inspection Guide

nachi.org — Home inspector reference on drainage and grading standards relevant to gravel projects

National Stone, Sand & Gravel Association — Consumer Resources

nssga.org — Industry association reference on aggregate materials and standards

External links open in a new tab. OmniCalc.us is not affiliated with these organisations.

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