Crushed Stone Calculator
Estimate loose crushed-stone volume, order weight, and waste allowance for rectangular, circular, or elliptical areas.
Project inputs
Required crushed stone
Excel workbook is ready.
Calculation breakdown
| Measure | Raw requirement | Waste allowance | Order amount |
|---|---|---|---|
| Volume | 0.89 yd³ | 0.09 yd³ | 0.98 yd³ |
| Weight | 1.33 US tons | 0.13 US tons | 1.47 US tons |
How to use the crushed stone calculator
What this calculator does
This calculator estimates the loose volume and approximate weight of crushed stone needed to cover or fill a simple rectangular, circular, or elliptical area. It is useful for early ordering and budgeting for driveway bases, paths, drainage beds, patio subbases, utility trenches, and landscape areas. It does not determine structural pavement thickness, drainage design, aggregate gradation, compaction specifications, or whether the subgrade is suitable. Those decisions depend on the project and local requirements. The Federal Highway Administration's granular-base guidance explains why aggregate bases are commonly placed and compacted in layers.
When to use it
Use the estimate before requesting quarry quotes, comparing bagged stone with bulk delivery, checking whether a truck-load minimum is sensible, or confirming that a planned depth is consistent across an area. For irregular projects, divide the site into several simple shapes, calculate each separately, and add the order amounts.
How to calculate
- The calculator opens with a complete demonstration: a 12 ft by 8 ft rectangle, 3 in deep, with 10% waste and a planning density of 1.5 US tons per cubic yard. Its example Excel workbook is immediately available.
- Select Surface shape. For a rectangle, enter length and width. For a circle, enter its diameter in Surface length; Surface width is ignored. For an ellipse, enter the two diameters.
- Replace Surface length, Surface width, and Depth with positive decimal values in feet, feet, and inches. Enter ordinary decimal notation such as 12, 8.5, or 3.25; scientific notation and decimal commas are rejected.
- Set Waste factor from 0% to 100%. It increases the geometric quantity for trimming, uneven edges, minor grade variation, and handling loss. Then set Bulk density in US tons per cubic yard using a value supplied for the exact product whenever possible.
- Read Order quantity as loose cubic yards including waste. Review Estimated weight, Base volume, Waste allowance, and Surface area, then use the breakdown table to see volume and weight before and after waste.
- Select Download Excel to create a fresh workbook from the current validated inputs. Reset clears the demonstration and all calculated data; Excel download is then disabled until a complete valid project is entered again.
Input guide
Surface shape is required and chooses the area formula. Rectangle uses length × width; Circle uses π × diameter² ÷ 4; Ellipse uses π × length × width ÷ 4. A common mistake is entering a radius when the circle field expects a diameter. Surface length is required, accepts a positive decimal in feet, and might be 12 ft. Increasing it increases area, volume, and weight in direct proportion. Surface width is required for rectangles and ellipses, accepts a positive decimal in feet, and might be 8 ft; it is not used for a circle.
Depth is required in inches and might be 3 in. Because depth is converted to feet before multiplication, doubling depth doubles stone volume. Do not enter a finished elevation difference or compacted lift count unless it represents the intended stone layer. Waste factor is required, accepts 0 – 100%, and defaults to 10%. It is an ordering allowance, not a compaction factor. Bulk density is required, accepts a positive value in US tons per cubic yard, and uses 1.5 in the example. Higher density raises weight but does not change cubic-yard quantity. Different stone sizes, void content, and moisture can change bulk density, so a supplier value is better than a generic average.
Output guide
Order quantity is an estimate in cubic yards after waste. Estimated weight is the order quantity multiplied by bulk density, reported in US short tons. Base volume is the geometric requirement before waste; Waste allowance is the added volume; and Surface area is the plan area in square feet. The summary pills repeat shape, area, depth, and waste so the result remains tied to its assumptions. In the table, Raw requirement excludes waste, Waste allowance isolates the added amount, and Order amount is their sum. Zero waste is valid; zero dimensions or depth are not meaningful for an order and are rejected.
Worked example
For the startup rectangle, area is 12 ft × 8 ft = 96.00 ft². A 3 in layer equals 0.25 ft, so volume is 96 × 0.25 = 24 ft³. Dividing by 27 gives 0.8889 yd³. Adding 10% waste gives 0.9778 yd³, displayed as 0.98 yd³. At 1.5 US tons/yd³, estimated weight is 0.9778 × 1.5 = 1.4667 US tons, displayed as 1.47 US tons.
How the estimate works
Estimated weight (US tons) = order volume (yd³) × bulk density (US tons/yd³).
Dividing depth by 12 converts inches to feet, and dividing cubic feet by 27 converts to cubic yards. The calculation treats the layer as having a uniform depth. Real sites often have low spots, edge loss, and grading variation, which is why an explicit waste allowance is useful. The NIST overview of volume units provides context for cubic-unit conversions, while the USGS crushed stone information page describes crushed stone as an important mineral commodity.
Planning and ordering notes
Ask the supplier whether pricing is by cubic yard, US ton, metric tonne, bag, or truck load, and whether the quoted density is loose, compacted, wet, or dry. A calculator can reconcile volume and weight only when those definitions match. For base and subbase work, aggregate is typically spread and compacted in controlled lifts rather than placed as one deep loose layer. The FHWA aggregate base application description discusses the role of granular base and subbase layers in pavement systems.
Common mistakes include measuring only the longest and widest points of an irregular shape, confusing radius with diameter, entering inches as feet, using solid-rock density instead of bulk density, and treating waste percentage as compaction. When the project has several depth zones, calculate each zone separately. Round the purchasing quantity according to supplier increments and delivery constraints rather than relying only on the displayed two-decimal estimate.