Road base calculator
A road section 100 ft long and 12 ft wide with 6 inches of compacted base needs 600 cubic feet, which weigh 40 tons at 1.8 tons per cubic yard. Enter the density from your quarry ticket and get the yards and tons your supplier quotes. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Length
- 100
- Width
- 12
- Depth
- 6
- Density
- 1.8
- Length ft
- 100
- Width ft
- 12
- Compacted depth inches
- 6
- Area sqft
- 1,200
Road base is the compacted crushed-rock or recycled-aggregate layer that sits under asphalt, concrete, or a gravel wearing course on roads, parking lots, and heavy driveways. Quarries sell it by the cubic yard and weigh it in tons, but a takeoff is a rectangle: length along the alignment, width of the paved or graveled section, compacted lift thickness, and a bulk density from the supplier ticket. This calculator converts those four numbers into cubic yards of compacted fill and short-ton weight. Length and width are feet; compacted depth is inches, the unit civil specs use for four-to-eight-inch lifts; density is short tons per cubic yard. Cubic feet equal length times width times compacted depth divided by twelve; cubic yards divide that result by twenty-seven; tons multiply yards by density.
What the calculator returns and how compacted road-base volume is defined
Road-base volume here is the compacted aggregate-base-course needed to fill a rectangular roadway, parking aisle, or structural driveway to a uniform compacted depth, expressed in cubic feet and cubic yards, plus a short-ton weight derived from bulk density. Cubic yards are the unit bulk yards and dump-truck brokers use for class 2 aggregate base, crusher run, three-quarter-inch minus, recycled concrete, and similar structural products; cubic feet help you cross-check a small patch against bagged product when a short repair stays on the retail aisle.
The conversion is the identity used on every civil take-off sheet: one cubic yard equals twenty-seven cubic feet, and compacted depth in inches must be divided by twelve before multiplying by length and width in feet. Equivalently, cubic yards equal length times width times compacted depth in inches divided by three hundred twenty-four, because twelve times twenty-seven is three hundred twenty-four.
Weight in short tons multiplies that cubic-yard figure by the supplier’s bulk density in tons per cubic yard; compacted class 2 aggregate base often sits near one point seven to one point nine, while looser crusher run or recycled millings may sit lower. Treat the result as a planning estimate and round up slightly for irregular edges, turnout flares, or a modest waste allowance your supplier recommends.
Where compacted road-base estimates fit for civil work, quotes, and software
Civil estimators meet this problem when a new access road needs six to eight inches of compacted class 2 aggregate base under asphalt, when a parking lot is measured in feet but the bulk yard quotes tons, or when a rural driveway is rebuilt as a structural base rather than a decorative gravel wearing course.
Trade estimators use the same identity across dozens of jobs: measure length and width, pick a compacted depth from the civil or geotechnical schedule, convert to yards for the delivery truck, and multiply by the quarry density sheet for tons so the gate scale and the material take-off stay aligned.
Teachers and vocational trainers can pre-generate answer keys for modest roadway sizes without trusting opaque mobile apps that switch units mid-form or forget that compacted depth is inches while length and width are feet and bulk weight is tons per yard. Developers call the same contract from scripts to seed deterministic test vectors for road-base calculators, to normalise user-entered sizes before a cart suggests yardage or tonnage, or to satisfy programming-challenge statements that demand cubic yards and tons rather than a hand-waved “about twenty yards.”
Product tools use the rewrite when a superintendent types one hundred feet by twelve feet by six compacted inches at one point eight tons per yard and the UI must show yardage and a clean ton total before checkout. Pair it with unit converters when your tape is metric, with driveway-gravel or landscape-bed helpers when the same property will receive mixed finishes, and with other build helpers when you are assembling a small lab of free, deterministic planning tools for outdoor construction.
What you can do with it
New access-road aggregate base takeoff
Enter length and width in feet plus compacted depth in inches and the quarry density to know cubic yards for bulk delivery and tons for the scale ticket.
Contractor parking-lot base quotes
Feed measured length, width, specified compacted lift, and supplier density from a civil schedule to produce reproducible yardage and tonnage for bids.
FAQ
How is road-base volume and tonnage calculated?
Cubic feet = length (ft) × width (ft) × compacted depth (inches) / 12. Cubic yards = cubic feet / 27 (or length × width × compacted depth / 324). Tons = cubic yards × bulk density in tons per cubic yard.
What happens if length, width, compacted depth, or density is zero, negative, or missing?
Any of those four values that is not a positive number cannot define a physical compacted layer, so the tool never invents yardage or tons.
What density should I use for compacted road base?
Use your supplier’s bulk density in short tons per cubic yard. Compacted class 2 aggregate base often sits near 1.7–1.9; looser crusher run or recycled millings may need a lower value. There is no hidden default: density is required.
Does this add compaction, waste, swell, crown, or slope correction?
No. It returns pure geometric compacted volume and density-based tons only.
Is the road base calculator free?
The browser tool is free and runs locally.
Related tools
For developers — API access
Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.
API endpoint
Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.
Call it from your stack
curl -X POST https://api.kit.forhosting.com/build/road-base \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"length":100,"width":12,"depth":6,"density":1.8}'const res = await fetch("https://api.kit.forhosting.com/build/road-base", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"length": 100,
"width": 12,
"depth": 6,
"density": 1.8
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/build/road-base",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"length": 100,
"width": 12,
"depth": 6,
"density": 1.8
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/build/road-base", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"length":100,"width":12,"depth":6,"density":1.8}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"length":100,"width":12,"depth":6,"density":1.8}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/build/road-base", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"length": 100,
"width": 12,
"depth": 6,
"density": 1.8
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "build.road_base",
"status": "queued",
"_links": {
"result": "/tasks/tsk_…/result"
}
}The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.
Pricing
Published price — no tokens, no invented credits. A failed task is never charged.
Errors
| HTTP | Code | Meaning |
|---|---|---|
401 | unauthorized | Missing or invalid API key. |
402 | insufficient_balance | Your balance doesn't cover the task price. |
404 | unknown_type | That task type doesn't exist. |
429 | rate_limited | Too many requests. Use the webhook instead of polling. |
Technical notes
Any input that is not a positive number fails with invalid_input so a typo never invents a free load. The same arithmetic powers the free browser tool and the API at $0.002 per successful request.
What the calculator returns and how compacted road-base volume is defined
The calculator multiplies length by width by compacted depth over twelve for cubic feet, divides by twenty-seven for cubic yards, multiplies by density for tons, and returns JSON that echoes length_ft, width_ft, compacted_depth_inches, area_sqft, density_tons_per_yd3, volume_cu_ft, volume_cu_yd, tons, unit tags, the method tag, and a short formula string. There is no brand database, no swell or compaction-factor table, no crown or cross-slope correction, and no shopping cart: the page answers only the compacted volume and tonnage questions with stable numbers suitable for worksheets, contractor quotes, and API consumers that must match goldens run after run.
How inputs are read, validated, and kept reproducible
Always convert a tapered or L-shaped apron into simple rectangles first—sum the pieces—because the solver never triangulates polygons or reads CAD files. Preferred fields are length for the alignment in feet, width for the paved or graveled section in feet, depth for compacted lift thickness in inches, and density in short tons per cubic yard from the quarry ticket or a published typical for the product. Aliases such as length_ft, area_length, and l for length; width_ft and w for width; compacted_depth, depth_inches, inches, and thickness for compacted depth; and material_density, tons_per_yd, tons_per_cu_yd, and bulk_density for density are accepted so spreadsheets, query strings, and typed forms can reuse the same contract without renaming columns. Every numeric field must be finite and strictly positive; any input that is zero, negative, missing, or non-numeric is rejected with invalid_input so a zero-depth form field cannot silently claim free stone and a blank length cannot invent a road. An optional precision field, with aliases decimals and dp, chooses how many decimal places to expose for lengths, volumes, and tons, defaulting to four and capped at fifteen so JSON goldens stay stable across engines. Pair the free browser run on this page with the priced API when you need the identical mathematical result inside an automated pipeline without re-implementing the road-base formula yourself.
Where compacted road-base estimates fit for civil work, quotes, and software
On this page the work runs entirely in your browser; through the API each successful lookup costs $0.002, failed validation is not charged, and nothing is stored after the response returns. That split — free interactive exploration and a priced, identical API — matches the rest of the KIT tier-A catalog and lets you move from a Saturday sketch to an automated quoting pipeline without changing the mathematical result.
Integration use cases
Golden fixtures for civil apps
Developers generate known-good cubic-yard and ton cases plus deliberate non-positive input rejections for unit tests and CI.