# Saylor Innovations BMR & Body Metrics Calculator

> Saylor Innovations BMR & Body Metrics Calculator is a paid API for AI agents from saylorinnovations.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-18).

Calculates BMI, BMR, TDEE by activity level, healthy weight range, calories to lose or gain, body surface area, and ideal weight from basic biometric inputs

## Facts

- Endpoint: GET https://saylorinnovations.com/api/health/bmr?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/saylor-innovations-bmr-body-metrics-calculator-8d3cdff6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_NhTXQwGjs0VFlo1C0wwmP

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability saylor-innovations-bmr-body-metrics-calculator-8d3cdff6
```

Example prompt: What's my BMR and daily calorie needs? I'm a 32-year-old male, 180 cm tall, 85 kg, and I'd say I'm moderately active.

## When to prefer this

Choose this endpoint when you need a comprehensive body metrics calculation in a single call — covering BMI, BMR, TDEE, ideal weight, and body surface area together rather than calling separate health APIs. Ideal for fitness apps, health dashboards, nutrition planning agents, or any workflow where multiple biometric metrics are needed simultaneously from minimal inputs.

## Known failure modes

- Missing required query parameters (sex, age, weight, height) returns an error
- Invalid or out-of-range values (e.g. negative age, zero weight) may produce nonsensical results
- Unsupported activity level string falls back to sedentary default
- Imperial unit values passed without units=imperial flag produce incorrect calculations

## How this service works

BMI, healthy weight range, BMR, daily calories (TDEE) by activity level, calories to lose or gain, body surface area and ideal weight

## Output

A JSON object containing BMI value and category, BMR in kcal/day, TDEE in kcal/day (adjusted for activity level), activity factor multiplier, body surface area in square metres, ideal weight via Devine formula, height in cm, weight in kg, sex, age, and a note with contextual caveats about the result.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "sex",
      "age",
      "weight",
      "height"
     ],
     "properties": {
      "age": {
       "type": "string",
       "description": "Age in years"
      },
      "sex": {
       "type": "string",
       "description": "male or female"
      },
      "height": {
       "type": "string",
       "description": "Height in cm (inches if units=imperial)"
      },
      "weight": {
       "type": "string",
       "description": "Weight in kg (lb if units=imperial)"
      },
      "activity": {
       "type": "string",
       "description": "optional sedentary (default), light, moderate, active, very_active"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "json"
    },
    "example": {
     "type": "object",
     "required": [
      "bmi",
      "bmr_kcal_per_day",
      "tdee_kcal_per_day"
     ],
     "properties": {
      "age": {
       "type": "number",
       "description": "Age in years"
      },
      "bmi": {
       "type": "number",
       "description": "Body mass index"
      },
      "sex": {
       "type": "string",
       "description": "Sex used in the equations"
      },
      "note": {
       "type": "string",
       "description": "Caveat or context for reading the result"
      },
      "source": {
       "type": "string",
       "description": "Data source the values come from"
      },
      "activity": {
       "type": [
        "string",
        "null"
       ],
       "description": "Activity level used for TDEE"
      },
      "height_cm": {
       "type": [
        "number",
        "null"
       ],
       "description": "Height in centimetres"
      },
      "weight_kg": {
       "type": [
        "number",
        "null"
       ],
       "description": "Weight in kilograms"
      },
      "bmi_category": {
       "type": "string",
       "description": "Bmi category"
      },
      "activity_factor": {
       "type": [
        "number",
  
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/saylor-innovations-bmr-body-metrics-calculator-8d3cdff6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from saylorinnovations.com](https://www.zero.xyz/host/saylorinnovations.com/llms.txt)