{
 "$schema": "https://tonelva.com/api/v1/openapi.json",
 "id": "tools",
 "title": "Free blood pressure calculators",
 "description": "Five calculators that run entirely in the browser. No account, no upload, nothing transmitted — the arithmetic happens on the reader's device and the page has no server to send a reading to.",
 "url": "https://tonelva.com/api/v1/tools.json",
 "documentation": "https://tonelva.com/api/",
 "generated": "2026-09-17T06:58:39.859Z",
 "publisher": {
  "name": "Tonelva",
  "legal_name": "Vast Flow, LLP",
  "url": "https://tonelva.com/",
  "documentation": "https://tonelva.com/api/",
  "contact": "support@tonelva.com",
  "about": "https://tonelva.com/about/",
  "note": "Tonelva publishes reference material and free calculators, and builds a blood pressure diary app. It is not a clinical body and sets no thresholds of its own: every category here is quoted from a published guideline and cited to the society that issued it."
 },
 "licence": {
  "id": "CC-BY-4.0",
  "name": "Creative Commons Attribution 4.0 International",
  "url": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "Tonelva (https://tonelva.com)",
  "covers": "The compilation: the machine-readable encoding of the two classification tables, the derived formulas, the tool catalogue and every field of this API. Use it commercially, modify it, redistribute it; credit Tonelva with a link.",
  "does_not_cover": "The guidelines themselves. The thresholds are quoted from the documents cited on each table; the societies that published them hold their own rights in those documents."
 },
 "upstream_sources": [
  {
   "id": "aha-2017",
   "name": "2017 ACC/AHA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults",
   "publisher": "American College of Cardiology / American Heart Association",
   "doi": "10.1161/HYP.0000000000000065",
   "url": "https://doi.org/10.1161/HYP.0000000000000065",
   "asOf": "2017-11-13"
  },
  {
   "id": "esc-esh-2018",
   "name": "2018 ESC/ESH Guidelines for the management of arterial hypertension",
   "publisher": "European Society of Cardiology / European Society of Hypertension",
   "doi": "10.1093/eurheartj/ehy339",
   "url": "https://doi.org/10.1093/eurheartj/ehy339",
   "citation": "European Heart Journal 39(33), 3021–3104, 25 August 2018.",
   "asOf": "2018-08-25",
   "superseded_in_part_by": "2024 ESC Guidelines for the management of elevated blood pressure and hypertension"
  },
  {
   "id": "home-monitoring-protocol",
   "name": "Home blood pressure monitoring protocol: seven consecutive mornings and evenings, duplicate readings, first day discarded",
   "publisher": "Common to the ACC/AHA, ESC/ESH and ESH home-monitoring guidance",
   "url": "https://tonelva.com/vitals/home-blood-pressure-monitoring/",
   "asOf": "2018-08-25"
  }
 ],
 "scope_limits": {
  "no_diagnosis": "A category is a label for one measurement, not a diagnosis. Hypertension is diagnosed from repeated readings, usually taken away from a clinic, interpreted by a doctor.",
  "no_treatment": "Nothing here recommends, starts, stops or adjusts medication, and no target figure here is a personal target. Targets are set by the clinician managing that person's care.",
  "no_measurement": "Tonelva records readings from a cuff. Neither the app nor a phone measures blood pressure, and any product claiming to do so from a camera or a fingertip is not measuring it either.",
  "emergency": "A reading above 180 systolic or 120 diastolic together with chest pain, breathlessness, weakness, vision change or confusion is emergency care, not a diary entry.",
  "two_frameworks": "Every classification returns BOTH the 2017 ACC/AHA and the 2018 ESC/ESH category. Reporting one without the other is how a reader ends up with two reputable sources that contradict each other and no way to reconcile them."
 },
 "not_published": [
  {
   "what": "The competitor app snapshot behind /compare/ — ratings, prices, release dates and store descriptions.",
   "why": "That metadata comes from the Apple App Store and is Apple's to license, not ours, and the descriptions are each publisher's own marketing. Republishing either keyless and CC BY would relicense content we do not own and distribute our competitors' copy at our cost.",
   "instead": "https://tonelva.com/compare/"
  },
  {
   "what": "Any blood pressure reading entered by anyone, in the app or in a calculator on this site.",
   "why": "There is nothing to publish. The calculators run entirely in the browser and transmit nothing; the app keeps its diary on the device. No reading reaches a server that could publish it, and publishing one is not something a user agreed to.",
   "instead": "https://tonelva.com/privacy/"
  },
  {
   "what": "Population statistics on blood pressure — prevalence, distribution by age, outcome rates.",
   "why": "Tonelva measures nothing and holds no cohort. Quoting such figures from a dataset we did not build would put our name on numbers we cannot stand behind.",
   "instead": "https://www.who.int/data/gho"
  }
 ],
 "count": 5,
 "computing_tools": 4,
 "callable_over_mcp": [
  "classify_reading",
  "mean_arterial_pressure",
  "pulse_pressure",
  "average_week"
 ],
 "mcp": "https://tonelva.com/mcp",
 "engine": "https://tonelva.com/js/engine.js",
 "note": "Every tool returns the category under BOTH guidelines where a category applies. A tool result is a label for a measurement, never an assessment of a person.",
 "data": [
  {
   "id": "blood-pressure-category-checker",
   "name": "Blood pressure category checker",
   "url": "https://tonelva.com/tools/blood-pressure-category-checker/",
   "mcp_tool": "classify_reading",
   "summary": "Classifies one reading under the 2017 ACC/AHA and the 2018 ESC/ESH tables at the same time, and says when the two disagree.",
   "takes": [
    "systolic (mmHg)",
    "diastolic (mmHg)"
   ],
   "returns": [
    "ACC/AHA category",
    "ESC/ESH category",
    "whether the frameworks disagree",
    "mean arterial pressure",
    "pulse pressure"
   ],
   "computes": true
  },
  {
   "id": "mean-arterial-pressure-calculator",
   "name": "Mean arterial pressure calculator",
   "url": "https://tonelva.com/tools/mean-arterial-pressure-calculator/",
   "mcp_tool": "mean_arterial_pressure",
   "summary": "MAP from a cuff reading, with the arithmetic printed so the figure can be checked rather than trusted.",
   "takes": [
    "systolic (mmHg)",
    "diastolic (mmHg)"
   ],
   "returns": [
    "MAP to one decimal",
    "the worked formula",
    "pulse pressure",
    "which band the result falls in"
   ],
   "computes": true
  },
  {
   "id": "pulse-pressure-calculator",
   "name": "Pulse pressure calculator",
   "url": "https://tonelva.com/tools/pulse-pressure-calculator/",
   "mcp_tool": "pulse_pressure",
   "summary": "The gap between the two numbers, its share of systolic, and whether it is narrow, usual or wide.",
   "takes": [
    "systolic (mmHg)",
    "diastolic (mmHg)",
    "age (optional, context only)"
   ],
   "returns": [
    "pulse pressure",
    "percentage of systolic",
    "narrow / usual / wide",
    "mean arterial pressure"
   ],
   "computes": true
  },
  {
   "id": "blood-pressure-average-calculator",
   "name": "7-day blood pressure average calculator",
   "url": "https://tonelva.com/tools/blood-pressure-average-calculator/",
   "mcp_tool": "average_week",
   "summary": "Averages a week of morning and evening readings under the home-monitoring protocol — which discards day one, the step almost everyone misses.",
   "takes": [
    "up to 14 readings, each with a day number and am/pm slot"
   ],
   "returns": [
    "the average",
    "morning and evening averages separately",
    "how many readings were discarded",
    "both categories for the average"
   ],
   "computes": true
  },
  {
   "id": "printable-blood-pressure-log",
   "name": "Printable blood pressure log",
   "url": "https://tonelva.com/tools/printable-blood-pressure-log/",
   "mcp_tool": null,
   "summary": "A dated log sheet to print and fill in by hand, one or two readings a day, one to eight weeks. It is a printable artefact rather than a computation, so it has no MCP tool.",
   "takes": [
    "a name",
    "a start date",
    "a number of weeks",
    "one or two readings a day"
   ],
   "returns": [
    "a printable sheet"
   ],
   "computes": false
  }
 ]
}