{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"vo2-max"},"result":{"entity_type":"calculator","id":"vo2-max","calculator_id":"vo2-max","canonical_url":"https://tttkmbb.com/fitness/vo2-max","name":"VO2 Max Calculator","title":"VO2 Max Estimate – Cooper 12-Minute Run Test and Heart-Rate Ratio Method","category":"fitness","category_name":"Sports & Fitness","tool_name":"estimate_vo2_max","featured_mcp_tool":false,"description":"Estimates maximal oxygen uptake (VO2max, ml/kg/min) from the distance covered in the Cooper 12-minute run test, and/or from the ratio of maximum to resting heart rate (Uth et al. 2004).","use_when":"You have a 12-minute run distance or resting and maximum heart rates and want a field estimate of aerobic fitness.","do_not_use_when":"A laboratory or wearable-measured VO2max is available, or the person cannot run continuously for 12 minutes; the heart-rate method also requires a true (measured) maximum heart rate.","inputs":[{"name":"distance_m","label":"12-minute run distance","type":"number","unit":"m","required":false,"min":600,"max":6000,"description":"Distance covered in 12 minutes of running (Cooper test). Omit if using heart rates only.","example":2800},{"name":"resting_heart_rate","label":"Resting heart rate","type":"number","unit":"bpm","required":false,"min":25,"max":150,"description":"Resting heart rate, measured on waking. Needed together with max_heart_rate for the heart-rate ratio method.","example":60},{"name":"max_heart_rate","label":"Maximum heart rate","type":"number","unit":"bpm","required":false,"min":80,"max":250,"description":"Measured maximum heart rate (an age formula such as 220 − age adds error).","example":180}],"outputs":[{"name":"vo2max_ml_kg_min","label":"VO2 max (estimate)","type":"number","unit":"ml/kg/min","decimals":1,"description":"Primary estimate: Cooper test when distance_m is given, otherwise the heart-rate ratio method."},{"name":"method","label":"Method used","type":"string","decimals":4,"description":"Which estimate is reported as primary."},{"name":"vo2max_cooper_ml_kg_min","label":"VO2 max (Cooper test)","type":"number","unit":"ml/kg/min","decimals":1,"description":"(distance_m − 504.9) / 44.73; only when distance_m is given."},{"name":"vo2max_heart_rate_ratio_ml_kg_min","label":"VO2 max (heart-rate ratio)","type":"number","unit":"ml/kg/min","decimals":1,"description":"15.3 × max_heart_rate / resting_heart_rate; only when both heart rates are given."}],"input_schema":{"type":"object","properties":{"distance_m":{"description":"Distance covered in 12 minutes of running (Cooper test). Omit if using heart rates only. Unit: m.","type":"number","minimum":600,"maximum":6000,"examples":[2800],"x-unit":"m"},"resting_heart_rate":{"description":"Resting heart rate, measured on waking. Needed together with max_heart_rate for the heart-rate ratio method. Unit: bpm.","type":"number","minimum":25,"maximum":150,"examples":[60],"x-unit":"bpm"},"max_heart_rate":{"description":"Measured maximum heart rate (an age formula such as 220 − age adds error). Unit: bpm.","type":"number","minimum":80,"maximum":250,"examples":[180],"x-unit":"bpm"}},"additionalProperties":false},"output_schema":{"type":"object","properties":{"vo2max_ml_kg_min":{"description":"Primary estimate: Cooper test when distance_m is given, otherwise the heart-rate ratio method. Unit: ml/kg/min.","type":"number","x-unit":"ml/kg/min"},"method":{"description":"Which estimate is reported as primary.","type":"string"},"vo2max_cooper_ml_kg_min":{"description":"(distance_m − 504.9) / 44.73; only when distance_m is given. Unit: ml/kg/min.","type":"number","x-unit":"ml/kg/min"},"vo2max_heart_rate_ratio_ml_kg_min":{"description":"15.3 × max_heart_rate / resting_heart_rate; only when both heart rates are given. Unit: ml/kg/min.","type":"number","x-unit":"ml/kg/min"}}},"formula":"Cooper: VO2max = (distance_m − 504.9) / 44.73; heart-rate ratio: VO2max = 15.3 × max_heart_rate / resting_heart_rate (ml/kg/min)","method":"Cooper (1968) correlated 12-minute run distance with treadmill VO2max in US Air Force personnel (r = 0.90). The heart-rate ratio method (Uth 2004) was derived in trained men; its standard error is about 4.5 ml/kg/min.","sources":[{"name":"Cooper KH (1968) A means of assessing maximal oxygen intake: correlation between field and treadmill testing, JAMA 203:201-204","url":"https://pubmed.ncbi.nlm.nih.gov/5694044/","type":"peer_reviewed","retrieved_at":"2026-09-24"},{"name":"Uth N et al. (2004) Estimation of VO2max from the ratio between HRmax and HRrest – the Heart Rate Ratio Method, Eur J Appl Physiol 91:111-115","url":"https://pubmed.ncbi.nlm.nih.gov/14624296/","type":"peer_reviewed","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"Cooper test 2800 m","inputs":{"distance_m":2800},"expected":{"vo2max_ml_kg_min":51.3,"vo2max_cooper_ml_kg_min":51.3,"method":"Cooper 12-minute run test"},"url":"https://tttkmbb.com/api/v1/calculate/vo2-max?distance_m=2800"},{"name":"Resting 60 bpm, max 180 bpm","inputs":{"resting_heart_rate":60,"max_heart_rate":180},"expected":{"vo2max_ml_kg_min":45.9,"vo2max_heart_rate_ratio_ml_kg_min":45.9,"method":"Heart-rate ratio (Uth 2004)"},"url":"https://tttkmbb.com/api/v1/calculate/vo2-max?resting_heart_rate=60&max_heart_rate=180"}],"faq":[{"q":"What is a good VO2 max?","a":"Population norms depend strongly on age and sex: roughly 35–45 ml/kg/min for healthy adults in their 30s, above 55 for well-trained endurance athletes and 70–85 for elites."},{"q":"Can I use 220 − age for the maximum heart rate?","a":"You can, but the individual error of age formulas (±10–12 bpm) propagates directly into the estimate; a measured maximum from an all-out effort is better."}],"tags":["vo2 max","cooper test","12 minute run","aerobic capacity","heart rate ratio method"],"related":[{"calculator_id":"heart-rate-zones","reason":"Training zones from the same maximum and resting heart rates."},{"calculator_id":"race-time-predictor","reason":"Predict race times from a known performance."}],"links":{"html":"https://tttkmbb.com/fitness/vo2-max","markdown":"https://tttkmbb.com/fitness/vo2-max.md","json":"https://tttkmbb.com/fitness/vo2-max.json","api":"https://tttkmbb.com/api/v1/calculate/vo2-max","schema":"https://tttkmbb.com/api/v1/calculators/vo2-max","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-23T23:33:40Z"}