How deep should a horse arena base be?

Rutgers Extension describes a base of four to six inches of compacted crushed stone placed under the footing material. Soft, wet or clay ground generally calls for a deeper base. The bands this calculator uses (4 to 6, 6 to 10 and 10 to 18 inches by subgrade) are working planning figures rather than published standards, so confirm the depth with a contractor or engineer.

How much aggregate do I need for an arena base?

Multiply arena length by width, multiply by the compacted base depth in feet, then divide by 27 for compacted cubic yards. Aggregate is delivered loose and compacts as it is rolled, so the loose volume to order is higher than the finished volume. This calculator adds a 20 percent allowance and estimates tons using 1.4 tons per cubic yard of compacted dense-graded aggregate; both are its own working approximations, so confirm them with your supplier.

Why order more aggregate than the finished base volume?

Because loose aggregate takes up more space than compacted aggregate, so a base specified at 6 inches compacted needs more loose material spread and rolled to finish at that depth. This calculator uses a 20 percent allowance, which is its own working figure. Ordering the compacted figure is an easy way to come up short.

What slope should an arena base have?

Rutgers Extension says the area should be sloped so water flows across it and not through the base. It gives no percentage, and the right grade depends on the site, so ask your contractor to specify one.

Horse property planning / Arena base

Horse Arena Base Calculator: Aggregate Tons by Arena Size

The layer under the footing decides whether the arena drains or ruts. Work out the compacted depth, the loose volume to order, and the tonnage before you call the quarry.

Step 01

Set the arena

Live estimate

Arena preset

Subgrade

Firm, well-drainedSand or gravel soils that stay solid wet. AverageHolds up most of the year, soft after heavy rain. Soft, wet or clayRutting, standing water, or heavy clay.

Base depth (compacted) 6 in

Planning band for average ground: 6 to 10 inches compacted. A working figure, not a published standard.

Waste factor (optional) %

Room for spillage, uneven subgrade, and edges. 0–15%.

Step 02

Calculated live

Your base estimate

Tons needed — tons of aggregate

Area: — sq ft
Volume: — cubic feet
Compacted: — cubic yards (finished, in place)
With 5% waste: — cubic yards loose | — tons

Based on 1.40 tons per cubic yard of compacted dense-graded aggregate.

Then comes the footing.

The base is the load-bearing layer. The footing is the cushion that sits on top of it, and the two are ordered separately.

Next step: work out the sand or blended footing with the horse arena footing calculator.

Common questions

What people get wrong about the base.

How deep should a horse arena base be?: Rutgers Extension describes a base of four to six inches of compacted crushed stone placed under the footing material. Soft, wet or clay ground generally calls for a deeper base. The bands this calculator uses (4 to 6, 6 to 10 and 10 to 18 inches by subgrade) are working planning figures rather than published standards, so confirm the depth with a contractor or engineer.
How much aggregate do I need for an arena base?: Multiply arena length by width, multiply by the compacted base depth in feet, then divide by 27 for compacted cubic yards. Aggregate is delivered loose and compacts as it is rolled, so the loose volume to order is higher than the finished volume. This calculator adds a 20 percent allowance and estimates tons using 1.4 tons per cubic yard of compacted dense-graded aggregate; both are its own working approximations, so confirm them with your supplier.
Why order more aggregate than the finished base volume?: Because loose aggregate takes up more space than compacted aggregate, so a base specified at 6 inches compacted needs more loose material spread and rolled to finish at that depth. This calculator uses a 20 percent allowance, which is its own working figure. Ordering the compacted figure is an easy way to come up short.
What slope should an arena base have?: Rutgers Extension says the area should be sloped so water flows across it and not through the base. It gives no percentage, and the right grade depends on the site, so ask your contractor to specify one.

Read the guidance

Sources worth keeping nearby.

NRCS AEN-4 Earth and Aggregate Surfacing Design Guide
Penn State Extension Riding Arena Footing Material Selection and Management
Rutgers E296 Horse Facilities