{"uid":"cap_pHCPjiVSgoIE26bOUeI7C","slug":"magent-bri-calculator-2d51ec9e","name":"magent BRI Calculator","description":"Body roundness index from height and waist (Thomas 2013). Models the body as an ellipse: e = sqrt(1 - (waist/(pi*height))^2), BRI = 364.2 - 365.5*e. Deterministic published formula with citation. Not a medical device, VAT measurement, or body-fat diagnosis; magent does not measure the patient.","url":"https://api.magentlab.com/api/calc/bri","method":"GET","headers":{},"bodySchema":{"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","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["waist_cm"],"properties":{"waist_cm":{"type":"number","description":"Waist circumference in centimeters (40-200). Compared to height in cm after normalize."},"height_cm":{"type":"number","description":"Height in centimeters. Provide height_cm or height_in."},"height_in":{"type":"number","description":"Height in inches. Converted as cm = in * 2.54."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_4BSjD5-tabkWP8eTqVTAb","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes Body Roundness Index (BRI) from height and waist circumference using the Thomas 2013 ellipse formula","exampleAgentPrompt":"Calculate the Body Roundness Index for someone who is 175 cm tall with a waist circumference of 90 cm using the Thomas 2013 formula.","exampleUseCases":[{"title":"Population health screening workflow","prompt":"I'm running a health screening and need to compute BRI scores for patients. Can you calculate the BRI for a patient who is 68 inches tall with an 85 cm waist?"},{"title":"Fitness tracker body shape metric","prompt":"My user logged their measurements: height 180 cm and waist 78 cm — can you compute their Body Roundness Index so I can show it on their dashboard?"},{"title":"Clinical research anthropometric analysis","prompt":"For a study participant who is 162 cm tall and has a 95 cm waist circumference, what is their BRI score according to the Thomas 2013 ellipse model?"}],"resultDescription":"Returns a numeric Body Roundness Index (BRI) value computed from the Thomas 2013 formula: BRI = 364.2 - 365.5 * sqrt(1 - (waist/(pi*height))^2), where both measurements are normalized to the same unit. The response is a deterministic, reproducible score reflecting how 'round' the body shape is relative to a circle.","failureModes":["Missing waist_cm parameter returns a validation error","waist_cm outside plausible range (40–200 cm) may be rejected or produce out-of-range BRI","Neither height_cm nor height_in provided results in a missing-parameter error","Non-numeric inputs cause schema validation failure","Payment failure (402) if x402 USDC payment header is not included"],"whenToPreferThis":"Use this endpoint when you need a fast, reproducible, citation-backed BRI calculation (Thomas 2013) without building the formula yourself. Prefer it over body-fat or VAT estimation endpoints — this is purely an anthropometric index, not a diagnostic or body composition tool. Best suited for health apps, clinical research pipelines, and population screening workflows that need a standard BRI score from height and waist inputs.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T19:00:35.901Z","isFirstParty":false}