Cubic feet converter
One cubic foot is exactly 1,728 cubic inches: enter a volume in cubic feet and get cubic inches, cubic meters, liters and US gallons together, so crates, ducts, tanks and freight papers share one sheet. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Cubic feet
- 1
- Cubic inches
- 1,728
- Cubic meters
- 0.0283168466
- Liters
- 28.316846592
- Us gallons
- 7.4805194805
A cubic feet converter turns a US customary volume in cubic feet into the four equivalents people actually need on the same sheet: cubic inches for crate interiors and HVAC duct tables, cubic meters for SI drawings and international freight, liters for tanks and laboratory glassware, and US liquid gallons for cisterns, fuel, and water storage. Enter a finite non-negative volume in cubic feet.
Why cubic feet still need four companion units on one page
Cubic feet remain the everyday volume unit for US rooms, ductwork, shipping crates, mulch and soil quotes, refrigerator interiors, and natural-gas billing notes that still speak in cubic feet rather than cubic metres. The people who search for a cubic feet converter almost never want only one other unit.
A warehouse planner needs cubic inches to check whether a product fits a carton, a freight clerk needs cubic meters for an international bill of lading, a facilities engineer needs liters to size a buffer tank, and a well or cistern owner needs US gallons to compare capacity with pump curves and municipal rates. Serving those four companions from a single cubic-foot input is the landing that matches that search, not a general hub that asks the visitor to pick from and to units they may not remember.
The factors are definitional, not estimates. One foot is twelve inches, so one cubic foot is exactly one thousand seven hundred twenty-eight cubic inches. Since the 1959 international yard and pound agreement, one international foot is exactly zero point three zero four eight metres, so one cubic foot is exactly that length cubed: zero point zero two eight three one six eight four six five nine two cubic metres.
One cubic metre is one thousand liters, so the liter factor is twenty-eight point three one six eight four six five nine two. One US liquid gallon is defined as two hundred thirty-one cubic inches, so one cubic foot is one thousand seven hundred twenty-eight divided by two hundred thirty-one US gallons. Approximate mental shortcuts such as seven point four eight gallons per cubic foot introduce a scale error that shows up on a large tank.
Where a cubic-feet converter earns its keep, and what it is not
HVAC and commissioning sheets convert room or duct volumes in cubic feet into cubic inches for grille tables and into cubic meters when the same job also files SI drawings. Logistics teams convert crate cubic feet into cubic meters for ocean freight and into cubic inches for carton inner dimensions, then cross-check US gallons when the crate is actually a liquid tote. Well, cistern, and aquarium owners convert a quoted cubic-foot capacity into gallons and liters before buying a pump or a treatment kit.
Teachers and exam generators need a deterministic oracle that rejects a negative volume instead of silently returning a signed result a buggy grader might treat as success. This landing targets people searching for cubic feet converter, cubic feet to gallons, cubic feet to liters, cubic feet to cubic meters, or cubic feet to cubic inches with exact factors. It is not a general multi-unit volume hub, not a cubic-meters-to-cubic-feet primary form, not an imperial-gallon path, and not a gas energy converter that turns CCF into therms.
Prefer this capability when the input is already in cubic feet and you need the four companions in one call; if you must convert among many units with a from and a to selector, use a broader volume converter instead. Stay inside the absolute range so the multiplies cannot overflow into a non-finite result the solver must reject.
What you can do with it
HVAC, rooms, and duct take-offs
Turn a room or duct volume in cubic feet into cubic inches and cubic meters for equipment tables, SI drawings, and commissioning sheets with the same exact factors every row.
Wells, cisterns, and classroom checks
Homeowners and students convert a quoted cubic-foot capacity into gallons and liters, and reject negative input instead of inventing a signed volume.
FAQ
How many cubic inches, cubic meters, liters, and US gallons are in one cubic foot?
Exactly 1728 in³, 0.028316846592 m³, 28.316846592 L, and 1728/231 US gallons.
Does the cubic feet converter accept a negative volume?
No. A physical volume cannot be negative. Zero is allowed and converts to four zeros.
Are these US gallons or imperial gallons?
US liquid gallons only (231 cubic inches). Imperial (UK) gallons are larger and would mislead searchers who typed cubic feet to gallons for US tanks and cisterns.
Is the cubic feet converter free?
The browser tool is free and runs locally.
Why not just multiply by 7.48 to get gallons?
Because 7.48 is rounded. The exact factor is 1,728 divided by 231, about 7.480519480519 US gallons per cubic foot, and the shortcut's small error grows into a visible gap on a large tank or cistern.
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/cubic-feet \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"cubic_feet":1}'const res = await fetch("https://api.kit.forhosting.com/conv/cubic-feet", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"cubic_feet": 1
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/cubic-feet",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"cubic_feet": 1
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/cubic-feet", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"cubic_feet":1}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"cubic_feet":1}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/cubic-feet", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"cubic_feet": 1
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.cubic_feet",
"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.
Limits
max_abs | 1000000000000 |
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
The solver multiplies by exact definitional factors—twelve cubed for cubic inches, the international foot cubed for cubic meters, one thousand liters per cubic meter for liters, and two hundred thirty-one cubic inches per US gallon for gallons—then returns all four rounded magnitudes in one JSON object. Negative values and non-finite numbers fail with invalid_input instead of inventing a volume.
Input contract, exact factors, and what the response contains
Absolute values must stay within the published limit of one trillion. Round-trip sanity checks are easy: convert one cubic foot and confirm one thousand seven hundred twenty-eight cubic inches, zero point zero two eight three one six eight four six five nine two cubic meters, twenty-eight point three one six eight four six five nine two liters, and one thousand seven hundred twenty-eight over two hundred thirty-one US gallons after rounding; convert zero and confirm four zeros. Prefer sending bare numbers when you control the client; string numbers are accepted only when they match a strict finite numeric pattern without units, thousand separators, or currency symbols. Send a JSON body with one required finite non-negative number named cubic_feet. Aliases ft3, cu_ft, cubic_ft, value, volume, and ft_cubed are accepted so SDK clients and form posts can use the name that fits the product. On success the response echoes rounded cubic_feet and returns cubic_inches, cubic_meters, liters, and us_gallons as the four equivalent volumes, plus a formula string restating the four exact factors and a short English message you can paste into a worksheet. Failed validation—missing fields, non-finite numbers, bare plus or minus signs, non-numeric strings, negative volumes, values above the absolute limit, or a non-finite converted result—returns invalid_input and is never charged. Pricing is a flat $0.002 per successful request with unit item.
Where a cubic-feet converter earns its keep, and what it is not
Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when learners deliberately omit cubic_feet or pass text.
Integration use cases
Shipping crates and liquid totes
Convert crate cubic feet to cubic meters for freight notes and to US gallons or liters when the same crate is a tank or tote, then pin the JSON against hand work.
Technical questions
What happens if cubic_feet is missing or not a number?
The API returns invalid_input naming the problem (for example a missing cubic_feet field or a non-finite value). Failed tasks are not charged.