Pounds to stone converter
140 pounds is exactly 10 stone, because one stone is 14 pounds. Type the pounds from a scale, a fitness app or a weigh-in sheet and get the stone figure British readers expect, with no rounded shortcut. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Pounds
- 140
- Stone
- 10
- Factor
- 14
People in the United Kingdom still describe adult body weight in stone, while bathroom scales, shipping labels, and most United States fitness apps report only pounds. The conversion is a single exact division: one stone equals fourteen avoirdupois pounds, so stone equals pounds divided by fourteen. This pounds to stone converter applies that identity on every run, echoes the pounds you entered, and returns the stone result without calling a network or a model.
Why a dedicated pounds to stone page still earns its keep
The stone sits between the pound and the hundredweight in the British imperial mass system. Modern metrology treats one stone as exactly fourteen avoirdupois pounds, with no seasonal drift and no special factor for body weight versus parcels. That exactness is why a landing titled pounds to stone remains useful: searchers are not shopping for a twenty-unit laboratory matrix.
They have one number in pounds and they want that number restated in stone immediately, using the legal identity rather than a rounded rule of thumb. Fitness trackers, clinic forms, boxing and rugby weigh-in sheets, and relocation paperwork all move data between pound-first and stone-first audiences. Mental arithmetic that “divides by fourteen and rounds” is fine in a hallway and poor on a medical chart.
Routing through kilograms first adds extra rounding that can shift the displayed stone value by a tenth or more. Negative input is rejected because a negative body or parcel weight is not a convertible quantity here. Non-finite values are rejected for the same reason.
Reverse queries belong on a stone-to-pounds tool. This page stays pounds in, stone out.
How the conversion works and what you get back
Send a single required field named pounds. The value must be a finite number; numeric strings are trimmed and coerced. Zero is valid and yields zero stone.
Missing fields, empty strings, objects, arrays, and non-numeric text fail the same way and are not billed. On success the engine divides pounds by the constant fourteen and returns pounds (echoed), stone (the converted mass), factor (always 14), and formula (the readable identity stone equals pounds divided by 14). There is no unit dropdown, no temperature-style offset, and no reverse mode on this landing: the search contract is pounds to stone.
Fractional pounds such as one hundred seventy-five produce twelve and a half stone.
Where pounds-to-stone conversion shows up in real work
Health and fitness products that launch in the United States and later add United Kingdom users often store pounds internally while UK customers still think and speak in stone. Converting at display time keeps storage simple and the interface local. Sports clubs listing fighter or rugby weights for a British audience can map pound weigh-ins from international partners into stone columns without teaching every volunteer the fourteen-pound rule.
Data-migration jobs that import legacy United States records into systems that surface stone for UK clinicians can quarantine only rows that fail validation—negatives, garbage text, infinities—while converting the rest.
What you can do with it
UK-facing fitness dashboards
Keep pounds in storage for US-built apps, then convert to stone at render time so United Kingdom users see the unit they actually speak.
Weigh-in sheets for UK sports clubs
Map pound readings from international partners into stone columns for boxing, rugby, and gym listings without a volunteer-maintained spreadsheet formula.
FAQ
What is the exact formula from pounds to stone?
Stone equals pounds divided by 14. One UK stone is defined as exactly fourteen avoirdupois pounds; this converter uses that identity with no kilogram detour.
Are fractional pounds allowed?
Yes. Any finite non-negative decimal is accepted. For example, 175 pounds converts to 12.5 stone because 175 ÷ 14 = 12.5.
Why does a negative weight fail?
A negative pound value is not a convertible mass in this contract.
Can this tool convert stone back into pounds?
No. This capability is pounds → stone only, matching the pounds-to-stone search. Use a dedicated reverse converter if you need stone to pounds.
Why not convert pounds to stone through kilograms?
Because the detour adds extra rounding that can shift the stone figure by a tenth or more. Dividing the pounds directly by 14 is exact and keeps a medical chart or a weigh-in sheet consistent.
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/pounds-to-stone \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"pounds":140}'const res = await fetch("https://api.kit.forhosting.com/conv/pounds-to-stone", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"pounds": 140
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/conv/pounds-to-stone",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"pounds": 140
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/conv/pounds-to-stone", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"pounds":140}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"pounds":140}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/conv/pounds-to-stone", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"pounds": 140
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "conv.pounds_to_stone",
"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
Negative weights and non-finite tokens such as NaN or Infinity fail with invalid_input instead of a silent zero.
Why a dedicated pounds to stone page still earns its keep
This capability exists so browsers, scripts, and API jobs share one audited division, one required field, and one failure mode.
How the conversion works and what you get back
Aliases such as lbs, pound, lb, value, weight, mass, amount, and n are accepted so existing clients do not have to rename columns. Any negative number fails with invalid_input naming the pounds field. At $0.002 per successful API item the charge matches a tiny edge parse; the free in-browser path uses the same library so the web tool and the API never diverge. Use the structured JSON to fill form fields, normalize CSV columns, or pin contracts in tests without re-hardcoding the fourteen-pound rule in every service.
Where pounds-to-stone conversion shows up in real work
Logistics teams moving personal effects or sample parcels between North America and the UK sometimes receive pound estimates on one form and must print stone on another; batch-converting a column through the API avoids spreadsheet copy-paste drift. Whether you type one value on this pounds to stone page or automate thousands of conversions through prepaid balance, the contract stays the same: non-negative finite pounds in, exact stone out, hard fail on anything else. No silent zeros, no approximate lookup tables, and no hidden rounding steps beyond ordinary IEEE floating-point division by a small integer.
Integration use cases
Batch import of pound columns
Run exported pound fields through the API, reject negative or non-finite rows with invalid_input, and write clean stone values for UK analytics.
Technical questions
What does a pounds to stone API call cost?
The browser tool is free and runs locally. Successful API conversions use prepaid balance at the published $0.002 base price; failed validation is not charged.