Ideal body weight calculator
Estimates adult ideal body weight with the Devine formula from height and sex: a man 170 cm tall gets 65.94 kg, or 145.37 lb. It is a reference figure from clinical teaching and coursework, not a personal weight goal. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Height
- 170
- Sex
- Male
- Height (cm)
- 170
- Height in
- 66.93
- Ibw kg
- 65.94
- Ibw lb
- 145.37
This ideal body weight calculator estimates adult IBW with the classic Devine formula from standing height and sex. Male IBW in kilograms is fifty plus two point three times inches over five feet; female IBW is forty-five point five plus two point three times the same height excess. Height may be entered in centimetres, metres, or inches and is normalized before the arithmetic. The engine is fully deterministic: no network calls, no sampling, and no date-dependent shortcuts.
What Devine ideal weight means and what you get
Ideal body weight in the Devine sense is not a personal health goal derived from body composition, activity, or preference. It is a published linear estimate that maps adult height and binary sex coefficients onto a single mass in kilograms, historically used as a convenient reference in clinical teaching and in some pharmacokinetic discussions of lean-related dosing concepts.
The male equation starts at fifty kilograms for a five-foot stature and adds two point three kilograms for every additional inch; the female equation starts at forty-five point five kilograms with the same per-inch increment. Missing height or missing sex always fails because both fields are required for Devine. Non-positive height, heights outside the documented centimetre window after unit conversion, and unrecognized sex tokens also fail with field-named messages so a bad form cell does not become a wrong target weight.
Where Devine IBW fits in education, software, and planning tools
Students meet the Devine equations in nursing and pharmacy coursework when textbooks introduce ideal body weight before more nuanced lean-mass models. Product teams call the same contract from scripts to seed deterministic test vectors for health dashboards, to validate user-entered height before related calculators run, or to satisfy programming-challenge statements that demand a Devine estimate rather than a black-box app. Fitness and wellness demos sometimes show IBW next to measured weight purely as a historical reference, while reminding users that real goals depend on composition, medical context, and professional guidance.
Treat the output as an educational and engineering estimate: if clinical or research accuracy is required, prefer measured body composition, published dosing protocols, and a qualified professional. Pair this tool with BMI, lean-mass, or multi-formula ideal-weight helpers when you need related anthropometrics, and keep units honest so centimetres and inches are never mixed by accident when building forms.
What you can do with it
Coursework and exam checks
Compute Devine IBW from height and sex for nursing, pharmacy, or physiology homework with a reproducible formula string.
Form validation and planning demos
Normalize height units and sex, then return a single Devine target mass for educational demos and input-validation pipelines.
FAQ
What does the Devine ideal body weight calculator cost?
It is free in your browser on this page.
What happens if height or sex is missing?
Both height and sex are required to compute Devine ideal body weight.
Is Devine the same as Robinson or Miller ideal weight?
No. Those are different published coefficients. This calculator implements only Devine; use a multi-formula tool if you need side-by-side variants.
What height units are supported?
Values are converted before applying the Devine equation.
Is my Devine ideal weight a goal I should aim for?
No. It is a published linear estimate based only on height and sex, not a health goal built from body composition, activity or preference. It has long served as a convenient reference in clinical teaching and some dosing discussions.
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/health/ibw-devine \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"height":170,"sex":"male"}'const res = await fetch("https://api.kit.forhosting.com/health/ibw-devine", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"height": 170,
"sex": "male"
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/health/ibw-devine",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"height": 170,
"sex": "male"
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/health/ibw-devine", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"height":170,"sex":"male"}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"height":170,"sex":"male"}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/health/ibw-devine", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"height": 170,
"sex": "male"
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "health.ibw_devine",
"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
Use it free in the browser for quick checks and coursework, or call the API at $0.002 per successful request when apps, spreadsheets, and CI suites need reproducible Devine IBW values without re-implementing the coefficients by hand.
What Devine ideal body weight means and what the response contains
This calculator returns height_cm and height_in as normalized inputs, the resolved sex used for coefficients, ibw_kg and ibw_lb as the Devine mass in both common unit systems, the method tag devine, a human-readable formula string for the chosen sex, and the precision applied to rounded weight fields. There is no age term, no frame-size adjustment, no ethnicity factor, and no activity multiplier in this contract: the engine either computes a finite positive IBW inside the supported height limits or rejects the request with invalid_input.
How height and sex are read and how results stay reproducible
Sex accepts male, female, m, f, man, woman, and their plural forms after case folding. Optional leading plus signs and scientific notation on numeric height strings are allowed when they parse as finite decimals; embedded spaces, hex prefixes, and non-numeric tokens are rejected with a clear message. Height must be strictly positive and, after conversion, between fifty and three hundred centimetres. The preferred fields are height for the numeric stature and sex for the Devine coefficient set, with aliases height_cm, h, stature, and ht for height, and gender or sex_at_birth for sex. Optional height_unit accepts centimetres (default), metres, or inches so forms can reuse the same contract without pre-converting every cell. Zero, negative, or non-finite values fail with invalid_input and a message that names the offending field. An optional precision field, with aliases decimals and dp, chooses how many decimal places to expose for the weight outputs, defaulting to two and capped at fifteen so JSON goldens stay stable. Computation converts height to inches, subtracts sixty to get inches over five feet, multiplies by two point three, and adds the sex-specific base of fifty or forty-five point five kilograms, then multiplies by the pounds-per-kilogram factor for ibw_lb. Pair the free browser run on this page with the priced API when you need the identical mathematical result inside an automated pipeline.
Where Devine IBW fits in education, software, and planning tools
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 — matches the rest of the KIT tier-A catalog and lets you move from a classroom demo to an automated pipeline without changing the mathematical result.
Integration use cases
Deterministic test fixtures
Generate stable ibw_kg and ibw_lb fields for unit tests, health dashboards, and CI assertions without re-coding Devine.
Technical questions
Which formula is used?
The Devine formula: for males IBW = 50 + 2.3 × (height_in − 60) kg; for females IBW = 45.5 + 2.3 × (height_in − 60) kg, with height in inches.