{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"ski-length"},"result":{"entity_type":"calculator","id":"ski-length","calculator_id":"ski-length","canonical_url":"https://tttkmbb.com/fitness/ski-length","name":"Ski Length Calculator","title":"Ski Length Calculator – Recommended Alpine Ski Size from Height, Weight, Ability and Ski Type","category":"fitness","category_name":"Sports & Fitness","tool_name":"recommend_ski_length","featured_mcp_tool":false,"description":"Recommends an alpine ski length range from skier height, adjusted for ability (beginner 10–15 cm below height, intermediate 5–10 cm, advanced 0–5 cm), ski type (powder/freeride +5 cm, carving and park −5 cm) and body weight (over 90 kg +5 cm, under 60 kg −5 cm), following the logic of retailer size charts.","use_when":"Someone is buying or renting alpine skis and needs a length range or a single recommended length for their height, ability and ski type.","do_not_use_when":"You are sizing cross-country skis (sized by weight and technique), snowboards or children's skis, or the manufacturer publishes model-specific sizing (rocker profile, waist width and turn radius change the ideal length).","inputs":[{"name":"height_cm","label":"Height","type":"number","unit":"cm","required":true,"min":100,"max":230,"description":"Skier height in centimetres.","example":175},{"name":"weight_kg","label":"Weight","type":"number","unit":"kg","required":false,"min":20,"max":200,"description":"Optional body weight: above 90 kg adds 5 cm, below 60 kg subtracts 5 cm.","example":75},{"name":"skill","label":"Ability level","type":"enum","required":true,"values":[{"value":"beginner","label":"Beginner (10–15 cm below height)","aliases":["novice","first time"]},{"value":"intermediate","label":"Intermediate (5–10 cm below height)"},{"value":"advanced","label":"Advanced / expert (0–5 cm below height)","aliases":["expert"]}],"description":"Ability level; shorter skis turn more easily, longer skis are more stable at speed.","example":"intermediate"},{"name":"ski_type","label":"Ski type","type":"enum","required":false,"default":"all_mountain","values":[{"value":"all_mountain","label":"All-mountain (no adjustment)","aliases":["all mountain","allmountain"]},{"value":"carving_piste","label":"Carving / piste / frontside (−5 cm)","aliases":["carving","piste","frontside"]},{"value":"powder_freeride","label":"Powder / freeride (+5 cm)","aliases":["powder","freeride","big mountain"]},{"value":"park_freestyle","label":"Park / freestyle twin-tip (−5 cm)","aliases":["park","freestyle","twin tip"]},{"value":"touring","label":"Touring / backcountry (no adjustment)","aliases":["backcountry","alpine touring","skimo"]}],"description":"Intended use; wide powder skis run longer, carving and park skis shorter.","example":"all_mountain"}],"outputs":[{"name":"length_min_cm","label":"Minimum length","type":"number","unit":"cm","decimals":0,"description":"Lower end of the recommended range."},{"name":"length_max_cm","label":"Maximum length","type":"number","unit":"cm","decimals":0,"description":"Upper end of the recommended range."},{"name":"recommended_cm","label":"Recommended length","type":"number","unit":"cm","decimals":0,"description":"Midpoint of the range rounded to the nearest centimetre; pick the closest length the model is made in."},{"name":"length_range_text","label":"Range","type":"string","decimals":4,"description":"The range as text, e.g. '165–170 cm'."},{"name":"adjustment_cm","label":"Total adjustment","type":"number","unit":"cm","decimals":0,"description":"Sum of the ski-type and weight adjustments applied to the ability range."},{"name":"notes","label":"Notes","type":"string","decimals":4,"description":"Which base range and adjustments were applied."}],"input_schema":{"type":"object","properties":{"height_cm":{"description":"Skier height in centimetres. Unit: cm.","type":"number","minimum":100,"maximum":230,"examples":[175],"x-unit":"cm"},"weight_kg":{"description":"Optional body weight: above 90 kg adds 5 cm, below 60 kg subtracts 5 cm. Unit: kg.","type":"number","minimum":20,"maximum":200,"examples":[75],"x-unit":"kg"},"skill":{"description":"Ability level; shorter skis turn more easily, longer skis are more stable at speed.","type":"string","enum":["beginner","intermediate","advanced"],"examples":["intermediate"]},"ski_type":{"description":"Intended use; wide powder skis run longer, carving and park skis shorter.","type":"string","enum":["all_mountain","carving_piste","powder_freeride","park_freestyle","touring"],"default":"all_mountain","examples":["all_mountain"]}},"additionalProperties":false,"required":["height_cm","skill"]},"output_schema":{"type":"object","properties":{"length_min_cm":{"description":"Lower end of the recommended range. Unit: cm.","type":"number","x-unit":"cm"},"length_max_cm":{"description":"Upper end of the recommended range. Unit: cm.","type":"number","x-unit":"cm"},"recommended_cm":{"description":"Midpoint of the range rounded to the nearest centimetre; pick the closest length the model is made in. Unit: cm.","type":"number","x-unit":"cm"},"length_range_text":{"description":"The range as text, e.g. '165–170 cm'.","type":"string"},"adjustment_cm":{"description":"Sum of the ski-type and weight adjustments applied to the ability range. Unit: cm.","type":"number","x-unit":"cm"},"notes":{"description":"Which base range and adjustments were applied.","type":"string"}}},"formula":"base range = height_cm + [−15, −10] (beginner), [−10, −5] (intermediate) or [−5, 0] (advanced); adjustment = +5 (powder_freeride) | −5 (carving_piste, park_freestyle) | 0 (all_mountain, touring), plus +5 if weight_kg > 90 or −5 if weight_kg < 60; length_min/max = base + adjustment; recommended_cm = round((length_min + length_max) / 2)","method":"Follows the height-based sizing used by retailer charts: a beginner's ski reaches roughly the chin, an expert's the top of the head. Rockered and wide powder skis ski shorter than their length, so charts push them longer; twin-tips and carving skis are ridden shorter. Heavier skiers need more ski for stability, lighter skiers less.","sources":[{"name":"evo – Ski Size Chart & Calculator: how to choose ski length","url":"https://www.evo.com/guides/how-to-choose-skis-size-chart","type":"reference","retrieved_at":"2026-09-24"},{"name":"Wikipedia – Ski (alpine ski types and geometry)","url":"https://en.wikipedia.org/wiki/Ski","type":"reference","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":"175 cm, intermediate, all-mountain, 75 kg","inputs":{"height_cm":175,"weight_kg":75,"skill":"intermediate","ski_type":"all_mountain"},"expected":{"length_min_cm":165,"length_max_cm":170,"recommended_cm":168,"length_range_text":"165–170 cm","adjustment_cm":0},"url":"https://tttkmbb.com/api/v1/calculate/ski-length?height_cm=175&weight_kg=75&skill=intermediate&ski_type=all_mountain"},{"name":"180 cm, beginner, powder ski","inputs":{"height_cm":180,"skill":"beginner","ski_type":"powder_freeride"},"expected":{"length_min_cm":170,"length_max_cm":175,"recommended_cm":173,"adjustment_cm":5},"url":"https://tttkmbb.com/api/v1/calculate/ski-length?height_cm=180&skill=beginner&ski_type=powder_freeride"}],"faq":[{"q":"Should I round up or down between two available lengths?","a":"Longer for stability at speed, in powder or for a heavier skier; shorter for easier turn initiation, moguls, park or a cautious skier."},{"q":"Does weight matter more than height?","a":"Weight is a secondary correction here (±5 cm outside 60–90 kg); a much heavier or lighter skier than typical for their height should shift within the range accordingly."},{"q":"What about cross-country skis?","a":"Classic and skate skis are sized by body weight and camber stiffness, not by this alpine chart."}],"tags":["ski length","ski size chart","ski size calculator","alpine ski sizing","how long should my skis be"],"related":[{"calculator_id":"bike-frame-size","reason":"Equipment sizing from body measurements for cycling."},{"calculator_id":"mass","reason":"Convert body weight from pounds to kilograms for the weight adjustment."}],"links":{"html":"https://tttkmbb.com/fitness/ski-length","markdown":"https://tttkmbb.com/fitness/ski-length.md","json":"https://tttkmbb.com/fitness/ski-length.json","api":"https://tttkmbb.com/api/v1/calculate/ski-length","schema":"https://tttkmbb.com/api/v1/calculators/ski-length","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T03:45:02Z","next_actions":[{"tool":"run_calculator","calculator_id":"ski-length","reason":"Run Ski Length Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/fitness/ski-length.md"}}