Stone Calculator
Result
Coverage in square feet
- Coverage in square metres
- 11.16 m²
- Volume in cubic yards
- 0.74 yd³
- Volume in cubic metres
- 0.57 m³
- Density
- 1,600 kg/m³
This stone calculator answers the other version of the question: how much ground will a ton of stone cover? Enter the weight you have ordered or are about to order, the depth you want, and the material, and the result comes back as an area in square feet and square metres, with the volume the load occupies in cubic yards and cubic metres. It is the reverse of the usual calculation, and it is the one people ask when the lorry is already booked: one ton of crushed stone at 2 inches covers about 120 square feet, and that is the number that decides whether one load is enough for the driveway or whether two are needed. It is the same sum for any landscaping rock sold by weight: a ton of river rock around a bed and a ton of crushed stone on a drive differ only by their density, which is the third input. The coverage per ton also stands as a table below, at four depths, so the common questions can be answered without touching the inputs.
Coverage per short ton of crushed stone
| Depth (in) | Square feet per short ton | Square yards per short ton |
|---|---|---|
| 1 | 240.3 | 26.7 |
| 2 | 120.1 | 13.3 |
| 3 | 80.1 | 8.9 |
| 4 | 60.1 | 6.7 |
One short ton (2,000 lb) of crushed stone at 1,600 kg/m³, loose as delivered — no allowance for compaction, so a rolled layer finishes thinner than the depth you read here. Pea gravel and river rock are 4% to 6% lighter and therefore cover a little more. For a compacted depth, add 20% to 25% to the depth column before reading across.
Formula
Coverage (ft²) = weight (kg) ÷ density (kg/m³) × 35.315 ÷ (depth in inches ÷ 12)
- m
- Weight of stone, converted from short tons to kilograms
- ρ
- Bulk density of the material — 1,600 kg/m³ for crushed stone as it is delivered
- d
- Depth of the layer, in inches
Use it when the weight is the fixed thing — a ton bag on a pallet, a tipper load sold by weight, or the tail end of a delivery you want to spread out. Use the gravel calculator instead when the area is the fixed thing and the weight is what you are working out. The two pages share one density table, so the same stone at the same depth gives reciprocal answers: 120 square feet per ton one way, 1 ton per 120 square feet the other.
Worked examples
One short ton of crushed stone at 2 inches
- Weight: 1 short ton = 907.2 kg
- Volume: 907.2 ÷ 1,600 = 0.567 m³, or 0.74 yd³
- Depth: 2 inches = 0.1667 ft
- Coverage: 20.02 ft³ ÷ 0.1667 ft = 120.1 ft², or 11.16 m²
120 square feet is a path 3 feet wide and 40 feet long, or half of a single-car driveway apron. Depth is what moves this figure more than anything else: halve it to 1 inch and the same ton reaches 240 square feet.
Ten short tons at 3 inches — a driveway
- Weight: 10 short tons = 9,072 kg
- Volume: 9,072 ÷ 1,600 = 5.67 m³, or 7.42 yd³
- Depth: 3 inches = 0.25 ft
- Coverage: 200.2 ft³ ÷ 0.25 ft = 800.9 ft², or 74.41 m²
801 square feet at 3 inches is a driveway about 10 feet wide and 80 feet long. Three inches is a surface layer over a compacted base rather than a base itself — a driveway built from bare ground wants 4 to 6 inches of base course underneath this, which is a different order of quantity.
One short ton of pea gravel at 1 inch
- Weight: 1 short ton = 907.2 kg
- Volume: 907.2 ÷ 1,540 = 0.589 m³, or 0.77 yd³
- Depth: 1 inch = 0.0833 ft
- Coverage: 20.81 ft³ ÷ 0.0833 ft = 249.6 ft², or 23.19 m²
Pea gravel is the lightest of the three at 1,540 kg/m³, so a ton of it goes about 4% further than a ton of crushed stone — and it is laid thinner anyway, 1 to 2 inches for a path or a bed topper. Rounder stone also stays loose underfoot, which is comfortable on a path and unsuitable for anything with wheels.
Limitations
The densities are typical bulk figures (±5%), not specifications: the same crushed stone varies with the quarry, the gradation and how much water is in the pile, and limestone and granite are at opposite ends of the range. ±5% on the density is ±5% on the coverage. Compaction is the larger question and it runs the wrong way on this page. The depths and weights here describe loose material as it is tipped; once it is compacted, a layer laid at 2 inches finishes noticeably under 2 inches — so the area this page returns is the area you can cover with loose stone, and the finished layer will be thinner than you entered. If what you need is a finished compacted depth, add 20% to 25% to the depth before entering it. Depth is also the thing people get wrong most often on a reverse calculation: the answer is inversely proportional to it, so an inch of error at 2 inches is a 50% error in the area. This page gives no bag count, because stone at this scale is sold by the ton or the cubic yard rather than by the bag. If your question is the other way round — the area is known and you want the tonnage — use the gravel, river rock or driveway gravel calculator instead; they share this density table, so the two answers agree.
Frequently asked questions
- How much area does a ton of stone cover?
- About 120 square feet of crushed stone at 2 inches, and about 240 square feet at 1 inch — the coverage per ton is inversely proportional to the depth, so halving the depth doubles the area. At 3 inches a ton covers 80 square feet, and at 4 inches 60. Heavier stone covers slightly less: pea gravel at 1,540 kg/m³ goes about 4% further than crushed stone at 1,600.
- How much stone do I need for a driveway?
- This page answers the reverse of that. If you know the driveway area, use the driveway gravel calculator: a 10 by 80 foot driveway at 3 inches is about 10 tons of crushed stone. If you already have the tonnage, enter it here and 10 tons at 3 inches comes back as 801 square feet.
- Should I enter the depth before or after compaction?
- Enter the loose depth and read the answer as the area you can cover with loose stone. Compaction runs against you on this page: stone laid at 2 inches and then rolled finishes under 2 inches, so the finished layer is thinner than the figure you typed. For a finished compacted depth of 2 inches, enter 2.4 to 2.5 inches — adding 20% to 25% — and the area will come back smaller, which is the honest answer.
- How many square feet is a ton of pea gravel?
- About 250 square feet at 1 inch, or 125 at 2 inches. Pea gravel is lighter than crushed stone at 1,540 kg/m³, and it is normally laid thinner — 1 to 2 inches for a path or as a topper over soil — which is why a ton appears to go a long way. It is also round, so it will not lock together under a wheel.
- How thick should a layer of crushed stone be?
- One inch pressed into soil is a weed-suppressing dressing, 2 inches is a path or a bed topper, and 4 inches over a compacted base is a driveway surface. A driveway built from bare ground needs 4 to 6 inches of base course under that surface layer, in a larger stone, which is a separate order of quantity.
- Why is this the reverse of the other gravel calculators?
- Because the question is different. The gravel, river rock and driveway calculators take an area and return a tonnage, which is what you need when you are ordering. This one takes a tonnage and returns an area, which is what you need when the load is already booked or already on the ground. They share one density table, so the two directions agree to the pound.
References
- Approximate Conversions from U.S. Customary Measures to Metric — the chart behind the short ton, the inch and the square foot used here — National Institute of Standards and Technology
- The International System of Units (SI) brochure — the tonne is 1,000 kg and is accepted for use with SI, which is what the metric half of this page is written in — Bureau International des Poids et Mesures (BIPM)