Density converter
1000 kg/m³ is exactly 1 g/cm³. Enter a density in kg/m³, g/cm³, lb/ft³ or pounds per US gallon and read the same value in all four units at once, for lab sheets, drilling-mud reports and packaging specs. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Density magnitude to convert
- 1,000
- Input density unit
- kg_m3
- Output density unit
- g_cm3
- Result
- 1
- Kg per m3
- 1,000
- G per cm3
- 1
- Lb per ft3
- 62.4279605761
Density conversion between metric SI and common imperial engineering units is a daily chore in materials science labs, oilfield drilling mud reports, shipping and packaging specs, and secondary-school physics homework. People search for a density converter when they need kilograms per cubic meter next to grams per cubic centimeter, or pounds per cubic foot next to pounds per gallon, not a general multi-unit toolbox that also handles length and temperature. This capability accepts one finite amount plus from and to unit labels among kg/m³, g/cm³, lb/ft³, and lb/gal (US liquid gallon), bridges every conversion through kilograms per cubic meter so results stay consistent, and returns the target value together with the same density expressed in all four units. Unrecognized unit names are rejected with a clear validation error instead of silently guessing a nearby symbol.
How the density converter maps metric and imperial units through kg/m³
Start from the kilogram per cubic meter as the SI coherent unit of density and express every other unit as a fixed factor into kg/m³. One gram per cubic centimeter is exactly one thousand kilograms per cubic meter because one gram is one thousandth of a kilogram and one cubic centimeter is one millionth of a cubic meter.
The international avoirdupois pound is defined as exactly zero point four five three five nine two three seven kilograms, and the international foot is exactly zero point three zero four eight meters, so one cubic foot is zero point three zero four eight cubed cubic meters; dividing the pound by that volume gives the exact lb/ft³ factor into kg/m³ used here.
Pounds per gallon use the United States liquid gallon of two hundred thirty-one cubic inches, which equals three point seven eight five four one one seven eight four times ten to the minus three cubic meters; that is the gallon people mean when they write drilling-mud density in pounds per gallon or ppg on a US field report. This calculator never mixes those paths ad hoc.
It multiplies the input amount by the factor of the source unit to reach kg/m³, then divides by the factor of the target unit to produce the result. Because every path shares the same intermediate, converting water-like 1000 kg/m³ to g/cm³ and back, or comparing lb/ft³ to lb/gal, stays numerically consistent within ordinary floating-point precision.
The tool does not convert Imperial UK gallons, does not treat kg/L or g/mL as separate landings even though g/mL matches g/cm³ numerically, does not compute specific gravity against an arbitrary reference fluid, and does not fetch live material databases. It answers only the algebraic density unit conversion people mean when they type density converter into a search bar and expect kg/m³, g/cm³, lb/ft³, and lb/gal.
Where dedicated density conversion shows up in real work
Secondary-school and college physics and chemistry courses constantly assign problems that give a solid or fluid density on one scale and ask for another, often mixing lab-style g/cm³ with SI kg/m³ and construction-style lb/ft³ in the same worksheet. Oil and gas mud engineers report drilling-fluid density in pounds per gallon while design tools and SI-native models expect kilograms per cubic meter, so a single conversion pass keeps logs, well plans, and sensors aligned.
Packaging, shipping, and materials procurement teams normalize product and cargo density fields between metric datasheets and United States industrial specs before rate shopping or structural load checks. Laboratory and quality-control workflows step between g/cm³ for solids and kg/m³ for process fluids without reimplementing factors in every spreadsheet. If you later need mass-only conversion, general multi-category unit conversion, or temperature scales, treat those as separate search intents and landings rather than overloading this density converter page.
What you can do with it
Lab and materials datasheets
Normalize solid and fluid densities among kg/m³ and g/cm³ so SI reports and traditional lab notebooks stay consistent.
Drilling mud and process fluids
Convert pounds per gallon (ppg) to kg/m³ for SI models and back for field reports without hand-written factors.
Construction and packaging specs
Map lb/ft³ bulk density to metric units for international shipping labels, load calculations, and homework keys.
FAQ
What happens if I send an unrecognized unit?
The error message includes Unrecognized unit and lists the supported families so you can correct the label.
Is the gallon the US or UK gallon?
The Imperial UK gallon is a different unit and is not accepted.
How does 1 g/cm³ relate to kg/m³?
Exactly 1000 kg/m³. One gram is 0.001 kg and one cubic centimeter is 10⁻⁶ m³, so the ratio is exact.
What does it cost?
The browser tool is free and runs locally.
What is the density of water in pounds per cubic foot?
Pure water near 4 °C sits at about 62.4 lb/ft³, which matches roughly 8.34 pounds per US gallon and 1000 kg/m³. It is a handy check that your units are the right way round.
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/conv/density \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"amount":1000,"from":"kg_m3","to":"g_cm3"}'const res = await fetch("https://api.kit.forhosting.com/conv/density", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"amount": 1000,
"from": "kg_m3",
"to": "g_cm3"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/density",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"amount": 1000,
"from": "kg_m3",
"to": "g_cm3"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/density", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"amount":1000,"from":"kg_m3","to":"g_cm3"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"amount":1000,"from":"kg_m3","to":"g_cm3"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/density", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"amount": 1000,
"from": "kg_m3",
"to": "g_cm3"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.density",
"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
What you send and what you get back from the API and browser form
Send three fields: amount, a finite number for the density magnitude; from, a string naming the input unit; and to, a string naming the output unit. When a unit string is unknown the error message includes Unrecognized unit and lists the four supported families so clients can fix the label rather than guessing. Classic checks include one thousand kilograms per cubic meter becoming one gram per cubic centimeter, pure water near four degrees Celsius sitting at about sixty-two point four pounds per cubic foot, and eight point three four pounds per US gallon matching that same water density within ordinary rounding. Both unit fields accept short keys and everyday words in any common casing, including kg_m3 or kg/m3 or kilograms per cubic meter, g_cm3 or g/cm3 or g/cc or grams per cubic centimeter, lb_ft3 or lb/ft3 or pcf or pounds per cubic foot, and lb_gal or lb/gal or ppg or pounds per gallon. Missing fields, non-numeric amount strings, NaN, Infinity, and unrecognized unit labels fail with invalid_input and are not charged. On success the response echoes the cleaned amount, normalized from and to keys, the primary result in the target unit, the same density as kg_per_m3, g_per_cm3, lb_per_ft3, and lb_per_gal with twelve significant digits of stable precision, the SI factors used, the formula string, and method kg_m3_bridge. Pricing for successful API calls is the published base of $0.002 per item; validation failures do not consume prepaid balance.
Where dedicated density conversion shows up in real work
Data pipelines that ingest mixed IoT or ERP payloads with kg/m3, g/cm3, and pcf tags can call this capability once per reading instead of reimplementing the factors in every service. Because this capability is a pure parse engine, API pricing is the published base of $0.002 per successful item and failed validation does not consume balance.
Technical questions
Which density units does this converter support?
Kilograms per cubic meter (kg_m3), grams per cubic centimeter (g_cm3), pounds per cubic foot (lb_ft3), and pounds per US gallon (lb_gal). Common aliases such as g/cc, pcf, and ppg are accepted; the response normalizes to short keys.