Schofield BMR calculator
Estimate resting calories with the WHO Schofield equations, which need only weight, sex and age: a 30-year-old man of 70 kg falls in the 30 to 60 band and gets 1676.14 kcal a day. Useful when no height is at hand. Free in your browser.
- Free
- Runs in your browser
- No sign-up
- Your data stays on your device
Run — free
Worked example
- Weight
- 70
- Sex
- Male
- Age
- 30
- Bmr kcal day
- 1,676.14 kcal/day
- Equation
- schofield_who
- Weight (kg)
- 70
- Age (years)
- 30
Basal metabolic rate is the energy your body expends at complete rest to sustain vital processes—breathing, circulation, cellular repair and thermal regulation. The WHO Schofield equations, published in 1985 and adopted in FAO/WHO/UNU energy-requirement reports, estimate that daily calorie floor from three inputs only: body weight in kilograms, biological sex and chronological age, which selects one of six sex-specific age bands. Unlike equations that also need height or body-fat percentage, Schofield is deliberately weight-centric and remains a standard reference in public-health nutrition, pediatric growth work and many international guidelines.
What the WHO Schofield equations compute and why they still matter
The Schofield equations estimate basal metabolic rate in kilocalories per day as a linear function of body weight for a given sex and age band. For adult men aged eighteen to thirty the classic form is fifteen point zero five seven times weight in kilograms plus six hundred ninety-two point two; for adult women in the same band it is fourteen point eight one eight times weight plus four hundred eighty-six point six.
Separate coefficient pairs cover infants under three, children three to ten, adolescents ten to eighteen, adults thirty to sixty and adults sixty and older, with different slopes and intercepts for males and females in each band. Those twelve lines of arithmetic capture average resting expenditure observed in the compilation cohorts that underpinned the 1985 FAO/WHO/UNU report. The result is a resting energy floor, not total daily energy expenditure: it does not add exercise, non-exercise activity thermogenesis, the thermic effect of food or illness-related demand.
Public-health agencies, pediatric services and international nutrition programs still cite Schofield because the method needs only weight, sex and age—measurements that are cheap to collect in field surveys—and because the published tables are easy to audit line by line. Prefer Mifflin-St Jeor or Harris-Benedict when height is available and you want a modern adult-focused estimator; prefer Katch-McArdle when lean body mass is known. Prefer Schofield when protocol, guideline or curriculum explicitly calls for the WHO weight-based bands, or when height is unavailable.
How to read the Schofield result
Send three required fields: weight as a positive finite number in kilograms, sex as male or female (short forms m, f, man and woman are accepted), and age as a non-negative number of years at most one hundred thirty. Age is mapped to one of six half-open bands: under three years, three up to ten, ten up to eighteen, eighteen up to thirty, thirty up to sixty, and sixty and above. There is no network hop, model call or randomness, so latency stays in the pure edge-parse band.
Pair this result with your own activity multiplier—for example one point two sedentary through one point nine very active—if you need estimated total daily energy expenditure; this capability deliberately stops at basal metabolic rate so product copy and clinical tools stay honest about what was measured.
Where Schofield BMR fits in health, research and product workflows
Nutrition coaching apps that follow WHO-style tables can convert onboarding weight, sex and age into a defensible resting calorie number before suggesting macros, without forcing users to enter height when the protocol does not require it. Clinical research coordinators batch-convert study-subject anthropometrics into Schofield BMR for secondary analysis without spreading spreadsheet formulas that diverge by cell or by which age-band boundary a colleague chose by hand. Fitness platforms that already offer Mifflin or Harris-Benedict can add Schofield as a third transparent baseline so members compare methods side by side.
Insurance and employer wellness portals can pre-fill educational calculators without shipping proprietary engines or calling external nutrition APIs. The browser path is free for single checks: enter seventy kilograms, male, age thirty, and confirm the adult thirty-to-sixty band result against the published slope and intercept.
What you can do with it
WHO-style onboarding baselines
Convert weight, sex and age collected at signup into a Schofield BMR before building a meal plan or macro target.
Method comparison in wellness products
Show users a Schofield kcal/day figure next to Mifflin or Harris-Benedict so they see how equation choice shifts the floor.
FAQ
What does it cost?
The same calculation runs free in your browser on this page.
Which inputs does Schofield need?
Body weight in kilograms, biological sex (male or female) and age in years. Height is not used. Age selects one of six WHO age bands.
Is this total daily energy expenditure (TDEE)?
No. This returns basal metabolic rate only. Multiply by an activity factor yourself if you need estimated TDEE.
Why was my request rejected?
Weight must be a positive number. Age must be non-negative and at most 130. Sex must be male or female (or m/f/man/woman).
How does Schofield differ from Mifflin-St Jeor?
Schofield uses only weight, sex and age band with coefficients from the 1985 WHO compilation. Mifflin-St Jeor also uses height and a single adult formula. This capability implements Schofield only.
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/bmr-schofield \
-H "Authorization: Bearer $KIT_KEY" \
-H "Content-Type: application/json" \
-d '{"weight":70,"sex":"male","age":30}'const res = await fetch("https://api.kit.forhosting.com/health/bmr-schofield", {
method: "POST",
headers: {
"Authorization": `Bearer ${process.env.KIT_KEY}`,
"Content-Type": "application/json"
},
body: JSON.stringify({
"weight": 70,
"sex": "male",
"age": 30
})
});
const { task_id } = await res.json();import os, requests
res = requests.post(
"https://api.kit.forhosting.com/health/bmr-schofield",
headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
json={
"weight": 70,
"sex": "male",
"age": 30
},
)
task_id = res.json()["task_id"]<?php
$res = file_get_contents("https://api.kit.forhosting.com/health/bmr-schofield", false, stream_context_create([
"http" => [
"method" => "POST",
"header" => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
"content" => '{"weight":70,"sex":"male","age":30}',
],
]));
$task = json_decode($res, true);body := bytes.NewBufferString(`{"weight":70,"sex":"male","age":30}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/health/bmr-schofield", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)Example request
{
"weight": 70,
"sex": "male",
"age": 30
}Example response
{
"task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
"type": "health.bmr_schofield",
"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
This capability applies the published coefficients exactly, with no fitness-tracker guesswork, no third-party nutrition API and no hidden activity multipliers.
How to call the API and interpret the response fields
Aliases such as weight_kg, kg, mass, years, age_years and gender map to the same parameters so existing forms wire in without renaming. Non-positive weight fails immediately with invalid_input and is not charged; missing, unparseable or out-of-range age, and unrecognized sex, also raise invalid_input with a clear field name in the message. A successful response returns bmr_kcal_day rounded to two decimal places, the normalized sex, the numeric weight and age used, the age_band label, the slope and intercept applied, a human-readable formula string and the unit label kcal per day.
Where Schofield BMR fits in health, research and product workflows
Pediatric and school-health programs often work with weight-centric equations; exposing the band label and coefficients in the JSON makes audit trails trivial for supervisors. Developers embed the call in CRON jobs and webhooks so every service shares one definition of the Schofield coefficients instead of reimplementing float-sensitive multiplies that disagree on rounding. The API path costs $0.002 per successful request and is billed per item, which keeps bulk onboarding scripts cheap while still covering edge execution.
Integration use cases
Research and public-health pipelines
Batch-compute resting energy estimates with the published age-band coefficients and stable JSON for audit logs.