Concrete weight calculator
Two cubic feet of concrete at 150 pounds per cubic foot weigh 300 pounds. Enter the volume and the density from your mix ticket or lab test to know what a crane, a truck axle or a floor must carry. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Volume
- 2
- Density
- 150
- Volume unit
- ft3
- Density unit
- lb_ft3
- Volume ft3
- 2
- Density lb ft3
- 150
This concrete weight calculator converts the volume of a poured or precast element into its weight in pounds using the mix density you supply. Enter a strictly positive volume and a strictly positive mix density; the engine converts both into cubic feet and pounds per cubic foot when you send another unit, then multiplies them. Typical normal-weight concrete sits near 150 pounds per cubic foot, lightweight structural mixes sit lower, and heavyweight shielding mixes sit higher, but the calculator never invents a density for you.
How volume and mix density become pounds
The weight of a uniform concrete element is the product of its volume and the unit weight of the mix. In US construction that identity is almost always written in cubic feet and pounds per cubic foot: one cubic foot of normal-weight concrete is about 145 to 150 pounds, so one cubic yard — twenty-seven cubic feet — of the same mix is about 3915 to 4050 pounds before you add a waste factor.
Lightweight structural concrete can sit near 90 to 115 pounds per cubic foot; heavyweight mixes used for radiation shielding can exceed 180. This calculator does not hide a default mix: you send the density that the specification, the ready-mix ticket, or a laboratory unit-weight test actually gives. Volume may arrive in cubic feet, cubic yards, cubic metres, or cubic inches; density may arrive in pounds per cubic foot, kilograms per cubic metre, or pounds per cubic yard.
The engine converts everything to cubic feet and pounds per cubic foot using the international foot of 0.3048 metres exactly and the avoirdupois pound of 0.45359237 kilograms exactly, then multiplies. That conversion step is why one cubic metre at 2400 kilograms per cubic metre and one cubic yard at 150 pounds per cubic foot are both first-class inputs instead of a spreadsheet of hidden factors.
Reinforcement, embedded items, and trapped air after vibration are outside the identity: they change the as-placed mass, but they are not mix density, and inventing a bar schedule here would pretend the tool knows more than volume times unit weight.
Where a concrete weight calculator earns its keep
Estimators meet this calculation when a crane chart, a truck axle limit, or a floor live-load check needs the mass of a pour or a precast piece rather than its cubic yards alone. One cubic yard at 150 pounds per cubic foot is 4050 pounds; ten yards on a truck is already more than twenty tons before you count the barrel, which is why a volume-only slab helper is the wrong landing for the query concrete weight.
Inspectors convert a core or a cylinder volume and a laboratory density into a check mass. Education tools show why a cubic metre of 2400 kilogram-per-cubic-metre mix is not the same number of pounds as a cubic yard of 150 pound-per-cubic-foot mix until both are converted, and why a zero volume is an error instead of a quiet zero.
This is not a slab, wall, column, or footing volume from length times width times depth, and it is not a cement-bag count from a mix ratio: those are different search intents with different inputs. Pair it with volume helpers when you already know the cubic yards, and keep engineering judgement for waste, reinforcement, and moisture that your pour requires beyond the pure volume-times-density identity.
What you can do with it
Ready-mix truck and crane charts
Turn cubic yards and the ticket unit weight into pounds so axle limits and crane charts see mass, not only volume.
Laboratory unit-weight checks
Multiply a measured specimen volume by laboratory density to recover the check mass in pounds without a hidden spreadsheet factor.
FAQ
How do I calculate the weight of a concrete element in pounds?
Send a positive volume and a positive mix density. One cubic yard at 150 lb/ft³ is 27 × 150 = 4050 pounds.
What density should I use for normal-weight concrete?
A common planning figure is 150 pounds per cubic foot (about 2400 kg/m³). Use the specified or laboratory unit weight when you have it; this calculator does not assume a default mix density.
Can I enter cubic yards or cubic metres instead of cubic feet?
The engine converts to cubic feet and lb/ft³ before multiplying.
What happens if volume or density is zero or negative?
An element with no extent or a mix with no mass cannot define a useful weight, and the failure is not billed.
How much does a cubic yard of concrete weigh?
About 4050 pounds at 150 pounds per cubic foot, a typical normal-weight mix. Lightweight mixes weigh less and heavy shielding mixes more, so enter the density your mix actually has.
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/concrete-weight \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"volume":1,"density":150}'const res = await fetch("https://api.kit.forhosting.com/build/concrete-weight", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"volume": 1,
"density": 150
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/build/concrete-weight",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"volume": 1,
"density": 150
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/build/concrete-weight", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"volume":1,"density":150}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"volume":1,"density":150}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/build/concrete-weight", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"volume": 1,
"density": 150
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "build.concrete_weight",
"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
Zero or negative volume or density is rejected as invalid_input instead of a hollow zero weight.
How volume and mix density become pounds
Use a measured or specified density, keep volume and density strictly positive, and the pound figure is the same on a phone, in a notebook, and through the API.
Input contract, units, and error behaviour
A zero or negative volume or density fails with a message that the named field must be a positive number, matching the rule that an element with no extent or a mix with no mass cannot have a useful weight. An unknown unit string is rejected rather than guessed, so a closed enum on the form cannot silently become a wrong conversion. Failed validation is not billed. Keep requests small and pin the rounded pound figure in tests so goldens stay byte-stable across runtimes. POST a JSON body with two required fields. volume is the size of the element and must be a finite strictly positive number; aliases include vol, V, and cubic_volume. density is the mix unit weight and must also be a finite strictly positive number; aliases include rho, mix_density, unit_weight, and pcf. Optional volume_unit defaults to ft3 and must be one of ft3, yd3, m3, or in3 when sent. Optional density_unit defaults to lb_ft3 and must be one of lb_ft3, kg_m3, or lb_yd3 when sent. Missing fields, empty strings, non-finite values, and magnitudes above the supported ceiling fail with invalid_input naming the field. On success the body echoes the parsed volume, density, and units, reports the coherent intermediates volume_ft3 and density_lb_ft3, and returns weight_lb as the primary result, plus a short formula string for audit. Pair the free browser run on this page with the priced API when you need the identical mathematical result inside an automated take-off; nothing is stored after the response returns, and the work never leaves your isolate for a model or a network hop.
Where a concrete weight calculator earns its keep
Precasters convert mould volume and the specified unit weight into lifting points and trailer payloads. 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 — lets you move from a phone check at the plant to an automated pipeline without changing the mathematical result.
Integration use cases
Precast lifting and trailer payload
Convert mould volume and specified mix density into element weight before you pick lifting inserts or load a trailer.
Technical questions
What does the concrete weight calculator cost?
The browser tool is free. API requests use prepaid KIT balance at $0.002 per successful call; invalid input is not billed.