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Open-Graded Bedding Course Stone Calculator

Loose volume and delivered tonnage of the screeded No. 8 bedding course under permeable pavers, with the allowance for it closing up under compaction.

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SettingsSettings for this calculationUS
Market
Imperial · sales tax
Plan area of the permeable surface that this screeded course sits under.

Take the area between the edge restraints, not the excavation area. The bedding course stops at the restraint; the base and subbase below it usually run wider, so their quantities come off a different figure.

Screeded depth of the bedding course before the units go down — the reference detail is a nominal 50 mm (2 in).

Thickness tolerance here is tighter than it looks, because bedding depth turns directly into surface elevation once the pavers are compacted. A thick spot densifies further than a thin one and shows as a low unit that cannot be corrected from above.

Extra loose stone ordered to cover the course closing up when the units are compacted.

Screeded open-graded stone is placed loose and never precompacted, so the delivered volume exceeds the finished volume. There is no universal figure for the difference — it depends on gradation, screed technique and how much plate work the surface gets. Treat the value here as a starting allowance and reconcile it against what the first bay actually consumed.

Uncompacted bulk density of the delivered gradation, from the supplier's ticket or data sheet.

Open-graded stone is lighter in place than a dense-graded aggregate because the voids that make it work are voids you are not buying. Ask the quarry for the loose density of the specific gradation; a figure carried over from a crusher-run base will over-order.

Delivered bedding stone

9.73 tons

Medium confidence

Both the loose density and the densification allowance are site figures rather than constants. Order the first delivery against this estimate, screed one bay, and reconcile before the balance is called off.

Screeded stone volume to deliver
7.96 yd³
Course volume once the units are bedded and compacted
6.92 yd³
Volume the course loses to densification
1.04 yd³
Then change the inputs to see how far the answer moves.

Show calculation logic

How this was calculated

Formula source(s)

  • ASCE/T&DI 68-18, Permeable Interlocking Concrete Pavement, gives the bedding course as a screeded layer of open-graded No. 8 stone at a nominal 50 mm (2 in), laid to a uniform thickness and not compacted before the units are set
  • Loose (uncompacted) bulk density of the delivered stone is the supplier's figure for the gradation and quarry actually being used; it is entered here rather than assumed, because it varies with source and moisture
  • The densification allowance — the extra loose stone needed because a screeded course closes up when the pavers are plate-compacted — is a rule of thumb rather than a published coefficient; check it against the first bay laid and revise the order

Inputs used

Area of Pavement Being Bedded
1290 sq ft
Nominal Screeded Thickness
2 in
Densification Allowance (%)
15
Loose Bulk Density of the Stone
90.52 pcf

Intermediate steps

Screeded stone volume to deliver
7.96 yd³
Course volume once the units are bedded and compacted
6.92 yd³
Volume the course loses to densification
1.04 yd³
Final result9.73 tons

Confidence note: Both the loose density and the densification allowance are site figures rather than constants. Order the first delivery against this estimate, screed one bay, and reconcile before the balance is called off.

What this calculation does not cover

  • Covers the bedding course only — the No. 57 choker, the subbase and the joint fill are separate gradations bought separately.
  • Assumes a uniform screeded thickness across the whole area; a section that varies in depth has to be split and run per zone.

Estimated cost — your price

This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.

open-graded bedding stone 2 inopen-graded bedding stone 50.8 mmbase

Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.

Sources checked 2026-09-06 · in the site-wide review of 2026-09-06 · v1.0.1

Regulatory standards & verification citations3
  1. ASCE/T&DI 68-18, Permeable Interlocking Concrete Pavement, gives the bedding course as a screeded layer of open-graded No. 8 stone at a nominal 50 mm (2 in), laid to a uniform thickness and not compacted before the units are set
  2. Loose (uncompacted) bulk density of the delivered stone is the supplier's figure for the gradation and quarry actually being used; it is entered here rather than assumed, because it varies with source and moisture
  3. The densification allowance — the extra loose stone needed because a screeded course closes up when the pavers are plate-compacted — is a rule of thumb rather than a published coefficient; check it against the first bay laid and revise the order
Cite this page

Your workspace

Most jobs need more than one number. Add the calculators you need next and they open right here, underneath this one — your figures stay on screen and nothing is lost to a page change.

Now that you have the number

These guides cover the work this quantity is for — the first ones run this calculator inside the section that raises the question.

Called something else where you work? Sub-base / hardcore — the term in each market, how close the equivalence really is, and the standard that governs it.

How to calculate open-graded bedding course stone in 5 steps

  1. Area of Pavement Being BeddedPlan area of the permeable surface that this screeded course sits under.
  2. Nominal Screeded ThicknessScreeded depth of the bedding course before the units go down — the reference detail is a nominal 50 mm (2 in).
  3. Densification Allowance (%)Extra loose stone ordered to cover the course closing up when the units are compacted.
  4. Loose Bulk Density of the StoneUncompacted bulk density of the delivered gradation, from the supplier's ticket or data sheet.
  5. Delivered bedding stoneThe tool computes the delivered bedding stone from those figures and shows the formula, its sources, and a confidence rating alongside it.

Delivered bedding stone by area of pavement being bedded

Page defaults, not your figures above.

Area of Pavement Being BeddedDelivered bedding stone (tons)
1,000 sq ft7.42
1,500 sq ft11.1
2,000 sq ft14.8
2,500 sq ft18.6

Frequently asked questions

Why can't I bed permeable pavers on sand like a conventional patio?
Sand migrates. Placed over an open-graded base it works its way down into the coarse voids under traffic and vibration, and the storage layer you paid for gradually becomes a filter that holds water instead of passing it. The permeable detail beds on small open-graded stone for that reason, and the choker course below keeps the two gradations apart.
Should the bedding course be compacted before the units are set?
No. It is screeded to a uniform thickness and then left alone — nobody walks it, and no plate touches it until the pavers are down. Compaction happens through the units afterwards, which is exactly why the delivered quantity has to exceed the finished volume.
Where does the densification allowance come from?
Experience on the job, not a table. It represents the difference between loose stone tipped on a screed board and the same stone once the pavers above it have been plate-compacted. Fifteen percent is a common starting point; the honest way to set it is to measure what the first bay consumed against its area and thickness, then apply that ratio to the rest.
Does this quantity include the stone that fills the joints?
It does not. Joint and aperture fill is a separate operation with its own gradation, and it is topped up and recompacted repeatedly until the joints stop taking material — a quantity that depends on joint width and unit geometry rather than on bedding depth.
Preliminary estimate, not certified engineering. This tool produces an indicative quantity calculation for planning purposes only — it is not a certified structural analysis, a guaranteed material takeoff, or a substitute for building department approval. Always verify measurements on-site and have a licensed contractor or structural engineer review any load-bearing, code-sensitive, or safety-critical work before purchasing materials or starting construction. Spotted an arithmetic or standards error? Report it to contact@craftquantities.com with your inputs — a confirmed fix gets a permanent check of its own, so the same mistake cannot come back.