Home » Gravel Size Chart and Different Types Explained with Pictures

Gravel Size Chart and Different Types Explained with Pictures

by Pablo

This post was last updated on July 24th, 2023 at 06:02 pm

The standard gravel size can vary depending on its intended use and regional standards. Gravel is generally categorized into different sizes based on the diameter of the individual stones. Commonly used sizes for gravel include:

  1. Pea Gravel: Typically 1/4 inch to 1/2 inch (about 0.6 cm to 1.3 cm) in diameter. It is often used for landscaping and pathways.
  2. Crushed Stone #5: Ranging from 1 inch to 1.5 inches (about 2.5 cm to 3.8 cm) in diameter. It’s commonly used as a base material for driveways and roads.
  3. Crushed Stone #57: Usually 3/4 inch to 1 inch (about 1.9 cm to 2.5 cm) in diameter. This size is commonly used for concrete mixes, drainage, and landscaping.
  4. Crushed Stone #411: Usually 1/2 inch (about 1.3 cm) in diameter. It’s commonly used for driveways, drainage, and concrete mixtures.
  5. River Gravel: Varied sizes, typically rounded and smooth due to natural erosion. River gravel is often used in landscaping and decorative applications.

Keep in mind that these sizes can vary based on local standards and preferences, so my advice is always best to check with local suppliers or construction guidelines for the most accurate information in your area.

Gravel Size Chart and Different Types Explained with Pictures size-charts.com
What is standard gravel size? Photo by Jon Moore on Unsplash

Gravel is a collection of loose, grey rock fragments that are naturally occurring or manufactured. You’ve probably seen these small dusty rocks in landscaping or road construction. Gravel doesn’t come in uniform sizes, and you’ll need thorough research before buying a ton of it for your project (skip straight to the Gravel Size Chart). 

If you get the gravel size right, there isn’t a limit to your applications. Gravel is useful for landscape decoration, soil erosion management, construction, and drainage. Learn what size of gravel you need from our gravel size chart below!

Jump right into the Frequently Asked Questions

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Table of Content of Gravel Sizing

Crushed stone vs gravel explained

What is Crushed Stone?

Crushed stone is a product of crushing rocks, making it angular in shape and texture. These stones are produced with the help of machines by mining and crushing natural rock. It is one of the most popular materials used in construction and landscaping projects due to its versatility. Crushed stone is commonly used as a base material for roads, driveways, and foundations and as a drainage option.

What is Gravel?

Gravel is a natural, rounded, and smooth-surfaced material formed from riverbeds or ancient deposits. It is available in various colors and sizes, making it suitable for functional and decorative purposes. Gravel is often used for pathways, landscaping, and as an aggregate in concrete.

Gravel vs crushed stone.
Gravel vs crushed stone. image Source: ZimmermanMulch

Gravel has a rounded shape and corners due to natural weathering and erosion. Whereas crushed stone usually has a boxy shape with more angular surfaces.

source: Naturallist

Type of Stone 

Many types of rock can be gravel! Some common types of rock for gravel include: 

  • Limestone 
  • Sandstone 
  • Basalt  
  • Granite

Gravel Size Chart

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Gravel and crushed stone size chart

Gravel numberSize in inchesSize in mm
#12 – 4 inches50.0 -102 mm
#20.5 – 2.5 inches13.0 – 63.5 mm
#30.5 – 2.0 inches13.0 – 50.0 mm
#41.0 – 2.5 inches25.0 – 63.5 mm
#5:1.0 inch25.0 mm
#8:0.4 – 0.5 inches 10.0 – 13.0 mm
#100.1 inches3.0 mm
#57 0.8 inches20.0 mm
#67less than 0.8 inchesLess than 20.0 mm
Type of GravelCharacteristicsBest UsesEdging Required?
Pea GravelSmall, rounded stones in natural colorsWalkways, driveways’ top layerYes
River RockSmooth and rounded gravel in natural shadesLandscaping, top layer of drivewaysYes
Lava RockPorous structure, comes in red, black, or grayWeed control, mulch, and aesthetic landscapingNo
Marble ChipsChipped marble in white and grayWalkways, driveways’ top layerYes
Jersey Shore GravelSmall, smooth gravel in golden colorDriveways, walks, landscaping in specific regionsYes

Note: Edging is recommended to prevent displacement of smooth gravel types like pea gravel, river rock, and marble chips.

Example picture of river rock
Example picture of river rock

How to Choose the Right Gravel Size

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Gravel sizes are based on the diameter in inches of the stones. Its size often determines its use and what it is called – pea gravel, river gravel, washed gravel, and river rock of various sizes. However, the correct size of gravel you need will depend on the application. This section will discuss the best use for the various stone grades.

#1 Gravel

This gravel size is the largest, featuring stones with a diameter of 2-4 inches (50 – 102 mm). Since they are large, it’ll be hard to shovel them, and you’ll have to place them one at a time. The common applications for this gravel grade include:

  • Making ballast
  • Filling larger holes
  • Reducing soil erosion
  • Lining ditches
  • As a decorative stone collection for gardens, patios, and yards

You can also use these rocks as the foundation for roads, driveways, and walkways but you’ll have to topdress them with stone dust. They can be unstable to walk on because of their size and require finer gravel for added stability. 

#2 Gravel

This gravel size is rare, and you won’t easily find it on the market. The rocks have a diameter of 1.5 – 2.5 inches (13 – 63.5 cm). Here are the common ways these crushed rocks are used:

  • Making ballast
  • Filling holes
  • Landscaping, and decoration
  • Septic tank filtration

#3 Gravel

Perhaps the most popular gravel size for home projects, #3 gravel has a diameter of 0.5 – 2 inches (13 – 50 mm). You can use them for:

  • Residential drainage projects
  • Making ballast
  • As a road base
  • On driveways
  • Filling dry wells
  • As a base in septic filtration systems

Using them in your driveway should also include stone screenings to ensure the ground is stable enough for movement. 

#4 Gravel

This gravel is about the size of a golf ball or an egg. It measures 1 – 2.5 inches (25 – 63.5 mm) in diameter and usually comes from crushed concrete. It can be a decoration or base for walkways when topdressed with fine gravel. 

#5 Gravel

You need this if you are looking for the ideal particle size range to fill crevices and the spaces between larger stones. The gravel measures about an inch in diameter and is ideal for driveways, walkways, and roads.

#8 Gravel or Coarse sand

These crushed stones measure between 0.4 and 0.5 inches (10 – 13 mm). Mostly, these stones go through cleaning to eliminate dust and residue, giving them a smoother appearance. Some common applications include:

  • Making asphalt
  • Creating concrete mixes during construction
  • As a subbase in patios, walkways, and driveways
  • As decoration around vegetation
  • As a base in horse barns
  • To assist in drainage

#10 Gravel

Also known as stone dust, gravel screenings, or rock screenings, #10 gravel is a by-product of the stone-breaking process. They are compact and easy to apply, making them suitable for the following:

  • As a paving base in stones, bricks, and concrete
  • Making concrete slabs and blocks
  • Filling spaces between larger rocks for stability
  • Top-dressing driveways and sidewalks

Screenings can quickly get dirty, so you shouldn’t use them in muddy places.

#57 Gravel

 This middle-range gravel size is easy to find and suitable for different functions. It measures about 0.75 inches (20 mm) and is ideal for any of the following uses:

  • Making hot-mix asphalt
  • RV parking pads
  • Driveways and parking lots
  • Landscaping purposes
  • Topdressing on a sub base
  • Making railroad ballast
  • Helping drainage
  • Lining underground paths for pipes and cables

My Pro tip: Use Jagged edge gravel for Driveways: Gravel with jagged edges may provide better interlocking and stability when used as a base material for driveways or pathways, as the irregular shapes can help create a firmer surface.

#67 Gravel

This gravel size is smaller than 0.75 inches (20 mm) and is among the smallest options. You can use it for:

  • Making concrete blocks and slabs
  • As a base on roads
  • Improving drainage around water systems
  • Stabilizing larger rocks
  • Retaining walls
Comparing-different-sizes-of-gravel-sand-pea-gravel-8-gravel-stone-chips-lime-stone
Comparing different sizes of gravel: Sand , Pea gravel , #8 gravel , stone chips , limestone

What are the Types of Gravel?

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Gravel comes in different forms. Let’s look at the various types of gravel you can buy. 

1. Bank Gravel

You can find this type of gravel naturally occurring in rivers and streams. It could be mixed up with the sand or natural soils on the river bank. Bank gravel is usually smooth and round and has an aesthetic look. 

2. Bench Gravel 

You’ll find bench gravel near valleys where streams flow by. It’ll indicate that the water levels are reducing, allowing the gravel to be visible instead of inside the stream. 

3. Crushed Stone

Unlike natural gravel, crushed stone is a by-product of the quarry process and is mostly used to surface roads and driveways. Crushed stone isn’t smooth; instead, it’s edgy and coarse.

4. Fine Gravel 

This is gravel with a very small diameter. It’s often used to stabilize the spaces between huge stones and road bases.

Pro tip: A common fine gravel type for French drains is “drainage gravel” or “drain rock.” The recommended size for drainage gravel in a French drain system is usually between 1/4 inch to 3/4 inch (about 0.6 cm to 1.9 cm) in diameter.

5. Stone Dust

As crushed stone goes through screens, the smallest are mixed with fine dust particles. 

6. Pay Gravel

This gravel type comes with a lot of precious metals like gold. Miners can extract the gold using a method called gold panning. 

7. Pea Gravel 

Pea gravel gets its name from its size and appearance. The gravel looks clean and about the size of a pea. 

Gravel and crushed stone sizing systems explained

ISO 14668 Gravel Size Categories:

ISO 14668 is an international standard that provides guidelines for classifying sedimentary materials, including gravel. The standard defines various size categories based on particle diameters. The gravel size categories in the ISO 14668 system are as follows:

  1. Very Coarse Gravel (GC): D50 > 200 mm – The median particle diameter (D50) is greater than 200 millimeters.
  2. Coarse Gravel (GC): D50 = 63 mm to 200 mm – The median particle diameter (D50) ranges from 63 millimeters to 200 millimeters.
  3. Medium Gravel (GM): D50 = 20 mm to 63 mm – The median particle diameter (D50) ranges from 20 millimeters to 63 millimeters.
  4. Fine Gravel (GF): D50 = 2 mm to 20 mm – The median particle diameter (D50) ranges from 2 to 20 millimeters.
  5. Very Fine Gravel (GVF): D50 < 2 mm – The median particle diameter (D50) is less than 2 millimeters.

Udden-Wentworth Scale Gravel Size Categories:

The Udden-Wentworth scale, also known as the Wentworth scale, is a widely used logarithmic scale for classifying sediment particle sizes, including gravel. It categorizes particles based on their diameters. The gravel size categories in the Udden-Wentworth scale system are as follows:

  1. Granule: 2 mm to 4 mm – Grains in this category fall between the sizes of sand and pebbles.
  2. Pebble: 4 mm to 64 mm – Pebbles are larger than granules but smaller than cobbles.
  3. Cobble: 64 mm to 256 mm – Cobbles are larger than pebbles but smaller than boulders.
  4. Boulder: Greater than 256 mm – Boulders are the largest category, with particles having diameters greater than 256 millimeters.

Learn more about Gravel Size Types and Sizes (video)

Gravel Types – Colors & Sizes by Cat in a Hammock

Frequently Asked Questions

1. What size is #1 gravel?

#1 gravel has a diameter of 2 – 4 inches (50 – 100 mm).

2. What size gravel is best?

The answer depends on your situation. Selecting the appropriate size of crushed stone and gravel is crucial to the success of any construction or landscaping project. The size determines the stone’s load-bearing capabilities, drainage properties, and aesthetics. The application you want will determine the right size of gravel to use. 

3. What size is #4 gravel?

#4 gravel measures about 1 – 2.5 inches in diameter (25 – 63.5 mm).

4. What size of gravel is best for a driveway?

#3 Gravel is the best size for driveways since it provides a stable platform and proper drainage thanks to its medium-sized diameter. 

5. What is 10mm gravel used for?

10mm gravel or #8 gravel is great for decorative purposes in your landscape. It adds interest, paves walkways, and suppresses weed growth. 

6. What area will 1 ton of gravel cover?

It depends on the gravel size. A ton of 0.3 – 0.5 inch gravel will approximately cover about 100 sq. ft at a depth of 2 inches. 

Conclusion

Gravel can be natural or artificial and comprises small rocks with various functions. These rocks come in different sizes, and you’ll need to determine the type of application before choosing gravel. Once you know the gravel size you want for your project, you can buy as much of it without fear.

Comment any questions about this topic below, and we’ll help you with any rocky situation!

Picture in this post is by Jon Moore on Unsplash

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