KM to feet converter
Multiply kilometers by 3280.839895 and get international feet: 1 km is 3280.839895 ft, built on the foot of exactly 0.3048 m. Made for US construction drawings, aviation obstacle reports and trail descriptions. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Km
- 1
- Result
- 3,280.839895 ft
- Converted
- 3,280.839895
- Feet
- 3,280.839895
- From unit
- km
A kilometres-to-feet converter turns a metric length into the international-foot magnitude still used on United States construction drawings, aviation obstacle reports, trail descriptions, and property surveys. Approximate mental shortcuts such as multiply by three thousand two hundred eighty-one are rejected in favour of this published constant, so homework checks and site plans match engineering tables.
Why kilometres and international feet still meet at 3280.839895
Kilometres belong to the SI-derived metric family used for road signs outside the United States, athletic race markings, mapping APIs, and most scientific distance reports. International feet remain standard on many United States construction drawings, aviation obstruction charts, hiking trail descriptions, property surveys, and building codes that still quote elevation and span in feet and inches.
The bridge between them is a single published multiplier: this capability multiplies kilometres by three thousand two hundred eighty point eight three nine eight nine five, which is the kilometres-to-feet constant that follows from one international foot being defined as exactly zero point three zero four eight metres and one kilometre being exactly one thousand metres.
Teachers and field crews often still teach the rough rule of thumb multiply by three thousand two hundred eighty-one, but that extra rounding drift shows up immediately on a ten-kilometre corridor or a five-hundred-kilometre pipeline alignment.
Practical tips, checks, and related searches
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. Round-trip sanity checks are easy: convert a known textbook value such as one kilometre and confirm you receive three thousand two hundred eighty point eight three nine eight nine five feet after rounding, or convert two point five kilometres and confirm eight thousand two hundred two point zero nine nine seven three seven five feet.
When teaching, pair the exact path with the mental shortcut so students see the drift on long alignments. Stay inside the absolute range so the multiply cannot overflow into a non-finite result the solver must reject. This landing targets people searching for km to feet conversion, convert kilometers to feet, or an exact three thousand two hundred eighty point eight three nine eight nine five calculator; it is not a general multi-unit length hub, not a feet-to-kilometres primary form, not a nautical-mile tool, and not an astronomical distance converter.
Prefer this capability when the input is already in kilometres and you only need international feet; if you must convert among many units in one call, use a broader unit converter instead.
What you can do with it
Construction and civil drawings
Turn metric alignment distances from survey exports into international feet for US-facing site plans, span tables, and elevation callouts with the same exact factor every row.
Trail, aviation, and obstacle reports
Hikers, GIS technicians, and aviation planners convert kilometre corridor lengths to feet and compare hand work against deterministic steps before publishing notices.
FAQ
What formula converts km to feet?
Feet = kilometres × 3280.839895. This capability uses that published constant so one kilometre always maps to 3280.839895 international feet.
Is 3280.839895 exact or approximate?
This tool treats 3280.839895 as the exact kilometres-to-feet factor. It does not use a US survey-foot variant or a rough multiply-by-3281 estimate.
Can I convert feet back to kilometres?
This capability is kilometres → feet only. Divide feet by 3280.839895 on your side, or use a bidirectional length converter for other units.
Is the km to feet conversion free?
The browser tool is free and runs locally.
How many feet are in 2.5 km?
2.5 km are 8202.0997375 feet. The converter multiplies any length in kilometers by 3280.839895, so a corridor, a trail or a runway gets its foot figure in a single step.
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/km-to-feet-conversion \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"km":1}'const res = await fetch("https://api.kit.forhosting.com/conv/km-to-feet-conversion", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"km": 1
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/km-to-feet-conversion",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"km": 1
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/km-to-feet-conversion", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"km":1}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"km":1}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/km-to-feet-conversion", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"km": 1
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.km_to_feet_conversion",
"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
Invalid or missing input fails with a clear invalid_input error instead of inventing a number.
How to call the API and what comes back
Absolute values must stay within the published limit of one trillion. Send a JSON body with one required finite number field named km. Aliases kilometers, kilometres, value, length, km_value, and distance are accepted so SDK clients and form posts can use the name that fits the product. On success the response echoes rounded km, sets feet, result, and converted to the same rounded foot magnitude, unit to the token ft, from_unit to km and to_unit to ft, factor and feet_per_km to the constant three thousand two hundred eighty point eight three nine eight nine five, formula to the string feet equals km times three thousand two hundred eighty point eight three nine eight nine five, message to a short English summary, and steps to an ordered array of substitution lines. Failed validation—missing fields, non-finite numbers, bare plus or minus signs, non-numeric strings, values outside absolute limits, 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. Keep payloads small: one number in, a compact JSON object out, no files and no side effects.
Practical tips, checks, and related searches
Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when learners deliberately omit km or pass text.
Integration use cases
Homework and unit-test fixtures
Students and engineers convert classroom kilometre readings to feet and pin golden JSON so browser and API arithmetic never drift.
Technical questions
What happens on missing or non-numeric input?
The API returns invalid_input naming the problem (for example a missing km field or a value that is not a finite number). Failed tasks are not charged.