Limestone Calculator
Work out the tonnage of crushed limestone an area needs — with compaction allowed for, so the finished depth is the depth you actually get.
Measure the area, name the finished depth
Give the shape of the ground and how deep the stone should be once it is rolled. The tonnage is what you order; the loose volume is what turns up on the truck.
How the limestone calculator works
A limestone calculator determines how much limestone you need for a project. Enter the area's length, width, and required depth to calculate limestone volume. Convert the volume to weight using the material's density. The required quantity varies by limestone type, compaction, project dimensions, and installation depth.
Everything else — cubic yards, bags, truck loads and cost — follows from that one weight figure. What separates a usable estimate from a short delivery is compaction. Crushed stone arrives loose and finishes dense, so the volume tipped on the ground is substantially larger than the layer it becomes. Working from the finished depth without allowing for that is the single most common way a driveway ends up an inch thin. This calculator reports the tonnage to order, the loose volume that will arrive, and the compacted volume it will become.
Rectangles, circles and rings all work. Awkward shapes split into pieces you can add up.
The depth after rolling, set by what the surface has to carry rather than by what looks right.
Compacted density gives the tonnage; the expansion factor gives the volume that turns up.
The formulas involved
Compacted volume
Vc = A × d
Area times the finished depth. For a ring, A = π(D² − d²) ÷ 4.
Tonnage to order
m = Vc × ρc × (1 + c/100)
Compacted density ρc, plus a percentage allowance for spread, settlement and edges.
Loose volume delivered
Vl = Vc × (1 + e/100)
The expansion factor e is what the same rock gains in bulk when it is not compacted.
Coverage per ton
A₁ = 1 ÷ (ρc × d)
How much ground one ton finishes at a given depth — the quickest sanity check there is.
Why weight and not volume: a ton is the same quantity of rock whether it is heaped on a truck or rolled into a driveway. A cubic yard is not. Quarry tickets, haulage rates and price lists are all written in tons for exactly that reason, and any estimate that ends in cubic yards has to be converted before it can be ordered.
Getting the area right
Measuring a driveway that isn't a rectangle
Area is where most estimates go wrong, not density. Real driveways flare at the road, bend around a corner, and widen where cars turn. The fix is always the same: cut the shape into pieces the calculator can handle, work each one out, and add the areas before you enter a single figure.
| Shape on the ground | How to measure it | Area |
|---|---|---|
| Tapered or flared drive | Width at each end, plus the length between them | (w₁ + w₂) ÷ 2 × L |
| L-shaped drive | Two rectangles — extend one fully and stop the other at its edge | A₁ + A₂ |
| Curved or sweeping drive | Walk a tape along the centre line, then the typical width | centre-line length × width |
| Turning area or apron | The rectangle it sits on, plus the rounded corner as a quarter circle | L × w + πr² ÷ 4 |
| Genuinely irregular | Measure the width every few paces along the length and average them | average width × L |
| Ring or path round a feature | Outer and inner diameter — the calculator has a ring option | π(D² − d²) ÷ 4 |
When two rectangles meet, the overlap belongs to one of them. Sketch it and shade each piece once.
Stone spreads at unrestrained edges. Measure where the surface will end up, not where the old one has crept to.
A surface crowned 4% is deeper down the middle. Enter the mean depth, or add roughly 10% for the extra.
Worked example: a drive 4 m wide at the house, flaring to 6 m at the road, over 18 m — that is (4 + 6) ÷ 2 × 18 = 90 m². Add a 3 m × 3 m parking spur and the total is 99 m². Enter 99 m² using the area I already measured option rather than guessing an average rectangle.
Choosing a grade
Clean stone or crusher run?
The difference that matters is not the rock, it is the gradation. Dense graded material keeps every particle size from the nominal down to dust, which lets it lock up hard under a roller. Clean stone has the fines washed out, so water runs through it and it never really compacts. Pick the wrong one and the surface either stays loose or holds water.
| Grade | Compacted | Loose expansion | Compacts? | Use it for |
|---|---|---|---|---|
| Dense graded base ¾ in | 1.83 t/yd³ | +40% | Yes, hard | Driveway surface and base, sub-base under slabs |
| Dense graded base 1¼ in | 1.89 t/yd³ | +43% | Yes, hard | Deeper base courses and heavier traffic |
| #57 clean stone | 1.35 t/yd³ | +8% | Barely | French drains, drainage layers, pipe bedding |
| Screenings / dust | 1.70 t/yd³ | +30% | Yes | Levelling course under pavers and flags |
| Rip rap, 3–6 in | 1.30 t/yd³ | None | No | Erosion control, swales, bank protection |
Names vary by region: crusher run, DGA, dense graded base, road base, MOT Type 1 and Class II base are broadly the same idea. Ask the quarry for the gradation rather than the local nickname.
Density reference: the dense graded base figures come from measured data — Wisconsin DOT's Weight-Volume Relationships and Conversion Factors for Soils and Aggregates of Wisconsin (2023) puts compacted ¾ in base at 1.80–1.86 tons per cubic yard and 1¼ in at 1.79–1.98, with compacted-to-loose expansion of 34–52%.
Coverage table
How far one ton goes
Finished area covered by a single ton, at the compacted densities above. Read down to your depth to check a quote before you accept it.
| Finished depth | Base ¾ in — ft²/ton | Base ¾ in — m²/tonne | #57 — ft²/ton | #57 — m²/tonne |
|---|---|---|---|---|
| 50 mm (2 in) | 89 | 9.2 | 120 | 12.5 |
| 75 mm (3 in) | 59 | 6.1 | 80 | 8.3 |
| 100 mm (4 in) | 44 | 4.6 | 60 | 6.2 |
| 150 mm (6 in) | 30 | 3.1 | 40 | 4.2 |
| 200 mm (8 in) | 22 | 2.3 | 30 | 3.1 |
The step estimates miss
Loose depth is not finished depth
Spread a 150 mm lift of crusher run, roll it properly, and you are left with something closer to 105 mm. Nothing has been lost — the voids between particles have closed. Every quantity on a delivery ticket refers to the loose state; every dimension on a drawing refers to the finished one.
Order against the tonnage
Weight does not change between loose and compacted, which is why it is the only figure worth putting on an order.
Spread in lifts
A roller only densifies what it can reach. Deep layers go down in lifts of roughly 100–150 mm, each compacted before the next.
Damp, not dry or wet
Dense graded stone reaches its density near optimum moisture. Bone dry material simply rearranges under the roller.
Clean stone is the exception: #57 and similar single-sized grades have no fines to fill the voids, so they barely densify. Compacting them is about seating the stones rather than reducing depth, and the expansion allowance is close to nothing.
Method reference: the Penn State Center for Dirt and Gravel Road Studies materials calculator takes the same approach — you specify either a compacted finished depth or a loose tailgated depth, and results come back as loose cubic yards together with as-shipped tons.
Before the stone arrives
What the ground underneath decides
Depth tables assume a subgrade that can hold the stone up. Where it cannot, extra tonnage is the expensive way to solve a problem that separation fabric solves cheaply.
Soft or wet subgrade
Stone pushed into mud is stone you never see again. Geotextile keeps the layers separate and the depth honest.
Shape it before you fill it
A crown of about 4% sheds water off the surface. Filling a flat, dished driveway with stone just relocates the puddle.
Edges need restraint
Without a kerb, timber or a cut edge, loose stone migrates outward and the middle thins every year.
Roads reference: the FHWA and South Dakota LTAP Gravel Roads Construction & Maintenance Guide recommends a crown near ½ inch per foot — about 4% — and never over 6%, and a minimum 6 inch first layer where geotextile is placed over a weak subgrade.
Layer by layer
How deep, and how many layers?
Almost nothing worth building is one layer of stone. A driveway is a coarse base carrying the load with a finer surface running over it, and the two use different grades at different densities. Working out a single combined depth and multiplying once gives the wrong weight — sometimes badly wrong, because a 1¼ in base and a screenings blinding differ by 30% per cubic yard.
Use the calculator once per layer. Same area, but the grade and finished depth change each time. Add the tonnages at the end — and order each grade separately, because they arrive on different trucks.
| Job | Bottom layer | Top layer | Total finished |
|---|---|---|---|
| New drive, firm ground | 100 mm (4 in) base 1¼ in | 75 mm (3 in) base ¾ in | 175 mm (7 in) |
| New drive, soft ground | Geotextile, then 150 mm (6 in) base 1¼ in | 75 mm (3 in) base ¾ in | 225 mm (9 in) |
| Topping an existing drive | Existing surface, raked and rolled | 50–75 mm (2–3 in) base ¾ in | 50–75 mm |
| Shed or slab sub-base | 100–150 mm (4–6 in) base ¾ in | 25–50 mm (1–2 in) screenings blinding | 125–200 mm |
| Paver or flag patio | 100 mm (4 in) base ¾ in | 25–40 mm (1–1½ in) screenings laying course | 125–140 mm |
| French drain | 100 mm (4 in) #57 under the pipe | #57 all the way up, geotextile wrapped | 300 mm (12 in) + |
| Heavy-use farm area | 150 mm (6 in) minimum, or twice the largest stone | 75 mm (3 in) ¾ in minus | 225 mm (9 in) + |
Lifts, not one deep dump
A roller only densifies what it can reach, so anything over about 150 mm goes down in lifts, each compacted before the next. NRCS puts the target at a CBR of 80, or roughly 125–135 lb per cubic foot, reached with three or four passes of a vibratory roller or crawler.
Coarse below, fine above
The larger stone carries the load and drains; the finer layer binds the surface and sheds water. Reversing them gives a drive that ruts under wheels and a base that never locks up. The one place fines are unwelcome is a drainage layer, which stays clean stone from top to bottom.
Thickness reference: the USDA NRCS Earth and Aggregate Surfacing Design Guide (TN 210-AEN-04, 2017) sets base course thickness as the greater of 6 inches or twice the D50 rock size, names ¾ inch minus as the standard crushed surfacing, and specifies compaction to CBR 80 or about 125–135 pcf.
Interesting fact
The most-moved rock on earth, at the price of gravel
Crushed stone is quietly the largest-volume mined commodity in the United States: an estimated 1.5 billion tons in 2025, worth $27 billion, from around 3,500 quarries. Roughly 70% of it is limestone and dolomite, and 72% of the total goes straight into construction aggregate, mostly roads. What makes the industry unusual is the economics — at an average of about $18.50 a metric ton, the rock is cheap enough that haulage distance dominates the delivered price. That is why quarries are scattered rather than concentrated, and why the sensible question when pricing a load is not which quarry is cheapest but which one is nearest.
Source: U.S. Geological Survey, Mineral Commodity Summaries 2026 — Stone (Crushed).
Buying it
Bags, bulk bags or a truck
Format changes the delivered price per ton far more than the grade does. Small bags cost several times bulk rate; a part load costs nearly as much to deliver as a full one.
What to settle before ordering
- Tonnage, not cubic yards — and get it on the ticket
- The gradation, not just the local name for it
- Whether the truck can reach and tip where you need it
- Haulage priced separately, and the minimum load
Rounding to a full load
If an estimate lands just over a truck's capacity, it is usually cheaper to trim the depth slightly than to pay for a second delivery of a few tons. The reverse is true too — where a job comes in a little under a full load, filling the truck often costs almost nothing per extra ton, and spare stone has a way of finding a use.
Worked example: a 40 × 10 ft driveway at 4 in finished, in ¾ in dense graded base · area 400 ft² · compacted volume 133.3 ft³ = 4.94 yd³ · at 1.83 t/yd³ that is 9.04 tons · plus 10% = 9.9 tons to order · arriving as roughly 6.9 loose cubic yards.
What it costs
Why the nearest quarry usually wins
Crushed stone is cheap and heavy, which makes it one of the few materials where the delivery costs more than the goods. Comparing quarries on their price per ton is therefore close to meaningless — the only number that decides anything is the price delivered to your gate.
| Haul distance | Haulage against the stone itself | What it means for the quote |
|---|---|---|
| Collected at the quarry | None — you supply the trailer | The cheapest stone there is, and rarely practical past a ton or two. |
| Under about 10 miles | Well below the cost of the stone | The ordinary case. Material price is worth shopping around on. |
| Around 25 miles | Roughly equal to the cost of the stone | Delivered price is about double the quarry price. The tipping point. |
| Beyond 25 miles | More than the stone costs | A nearer quarry with a worse headline price almost always wins. |
Part loads pay full freight
A truck costs much the same to send whether it carries 8 tons or 20. Filling the last third of a load is often the cheapest stone you will ever buy.
A second trip is the expensive mistake
Coming up three tons short means paying a whole delivery to fix it. That is what the allowance percentage in the calculator is buying you.
Bagged is a convenience price
Small bags run to several times the bulk rate per ton. They earn it only where access, storage or a very small quantity rules a tipper out.
What to ask for on the phone: the price per ton delivered to the postcode, the minimum load, whether tax is included, what the grade is called in their gradation rather than in local slang, and whether a tipper can reach the spot. Enter the delivered per-ton figure in the calculator's price box and the total it returns is the real one.
Economics reference: the 25-mile rule comes from the USGS survey of the industry — William H. Langer's Natural Aggregates of the Conterminous United States (Bulletin 1594) states that once aggregate moves more than 25 miles by truck, transport equals or exceeds the quarry price, with truck rates far higher for the first mile than for each mile after it. The dollar rates in that bulletin are of its era; the ratio is what has held.
Common mistakes to avoid
Estimating from the finished depth alone. The tonnage is right, but the pile that arrives looks far bigger than the hole — and if you spread it to the finished depth first, you will be a third short.
Using one density for every grade. Clean #57 and crusher run differ by nearly 40% per cubic yard. A single generic figure gets one of them badly wrong.
Laying a layer thinner than the stone. A 50 mm layer of 40 mm rock is a single course of loose stones, not a surface. Depth should comfortably exceed the largest particle.
Ignoring the subgrade. Stone laid on soft ground disappears into it. That loss shows up as a driveway that needs topping up every spring.
Frequently Asked Questions
How do you calculate how much limestone you need for a project?
Multiply the length by the width to get the area, then multiply that area by the finished depth to get the compacted volume. Multiply the volume by the compacted density of the material and you have the weight to order. A dense graded ¾ inch base runs about 1.83 tons per cubic yard compacted, so a 40 by 10 foot driveway — 400 square feet — at 4 inches deep comes to 133 cubic feet, just under 5 cubic yards, or roughly 9 tons. Order by weight rather than by volume wherever you can: quarries and hauliers sell by the ton, and a ton is the same quantity of rock however loosely it happens to be piled on the truck. The calculator runs the same arithmetic for any project, including the awkward shapes a tape measure struggles with.
How many tons of crushed limestone are in a cubic yard?
Between about 1.3 and 1.9 tons, depending on the grade and on whether the stone is loose or compacted — or roughly 1.5 to 2.3 tonnes per cubic meter in metric. Wisconsin DOT testing puts compacted dense graded base at 1.80 to 1.86 tons per cubic yard for the ¾ inch size and 1.79 to 1.98 for the 1¼ inch size. The same aggregate loose on a truck occupies 34 to 52 percent more space, which works out near 1.3 tons per loose cubic yard. That gap is why a load that looked ample on delivery gives less coverage than expected once compaction has done its work.
How deep should a limestone driveway, patio or walkway be?
A residential driveway usually wants a base course 100 to 150 mm (4 to 6 inches) thick, with a 75 to 100 mm (3 to 4 inch) surface layer over it, laid in lifts and compacted rather than dumped in one go. A garden walkway needs far less, around 50 to 80 mm. A patio or paver sub-base is typically 100 mm of dense graded stone under a thin screenings laying course, and a shed foundation or slab sub-base wants 100 to 150 mm. Soft or wet subgrade needs more thickness, and a geotextile underneath — the FHWA gravel roads guide recommends a minimum 150 mm first layer where fabric is used over a weak subgrade. Depth is a landscaping decision driven by what the surface has to carry, not by what looks right in the trench.
Why does compaction mean you need more material than the finished depth suggests?
Because the stone arrives loose and finishes dense. Rolling a dense graded aggregate closes the voids between particles, so the layer loses roughly a quarter to a third of its thickness between tipping and finishing. Wisconsin DOT measured the expansion from compacted to loose at 34 to 52 percent across the common base sizes. Estimating from the finished depth alone therefore leaves you short: the tonnage has to be worked out against the compacted density, and the volume of fill you watch arriving will be noticeably larger than the hole it goes into. Clean single-sized stone is the exception — with no fines to close up, compaction barely changes its depth at all.
What is the difference between #57 stone, crusher run and screenings?
#57 is a clean, single-sized gravel of roughly ¾ inch with the fines washed out, so it drains freely, locks together only loosely and never really compacts. Crusher run — also sold as dense graded aggregate or DGA — keeps the full range of particle sizes from ¾ inch down to dust, which is what lets it compact into a hard, tight base. Screenings are that fine end on their own, a dust-to-⅜-inch material used as a levelling course under pavers and flags rather than as a structural layer. Use crusher run where you want a firm surface to drive on, screenings where something has to be bedded flat, and #57 where water has to move through — a French drain, or a drainage sub-base beneath a slab.
Should limestone be ordered by the ton or by the cubic yard?
By the ton, in almost every case. Weight is unambiguous, it is what the weighbridge ticket records, and it does not change with how the load settles. Volume is useful for picturing the delivery and for checking that the truck can carry it, but a cubic yard of loose stone and a cubic yard of the same stone rolled into a driveway are two different quantities of rock. Cost follows weight as well: quarries quote per ton and haulage is charged on the same basis, so the delivered cost of a load is a weight figure from end to end. This calculator reports both, and treats the tonnage as the number to order against.
Before you place the order
- The area is measured, not paced out
- The depth entered is the finished one
- The grade matches the job — dense to drive on, clean to drain
- The layer is deeper than the largest stone in it
- The subgrade is shaped, drained and fabric laid if soft
- The order is in tons, with haulage priced separately
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Disclaimer
This calculator estimates material quantities for a uniform layer of crushed stone over a measured area. It does not model an uneven subgrade, ruts or hollows being filled, stone lost into soft ground, or the extra depth a crowned surface needs at the centre.
The densities offered are typical values for common grades. Limestone varies by quarry and by moisture content, and the dense graded base figures are drawn from Wisconsin measurements rather than from your supplier's material. Where the tonnage matters, ask the quarry for the conversion factor for the specific product and enter it as a custom density.
Depth guidance reflects common practice for residential and light-traffic work. Structural pavements, public roads and anything carrying heavy or repeated axle loads should be designed against the relevant highway or geotechnical specification rather than a rule of thumb.
Last updated
Densities, coverage figures, and references checked on this date.