{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"projector-throw"},"result":{"entity_type":"calculator","id":"projector-throw","calculator_id":"projector-throw","canonical_url":"https://tttkmbb.com/everyday/projector-throw","name":"Projector Throw Distance Calculator","title":"Projector Throw Distance Calculator – Distance, Image Width, Height and Diagonal from Throw Ratio","category":"everyday","category_name":"Everyday Life","tool_name":"calculate_projector_throw_distance","featured_mcp_tool":false,"description":"Uses a projector's throw ratio (distance ÷ image width) to find the projection distance for a given screen width, or the image width for a given distance, and reports the image height and diagonal for the chosen aspect ratio.","use_when":"You are placing a projector or choosing a screen size and know the lens throw ratio from the spec sheet, or want to know what throw ratio a room needs.","do_not_use_when":"You need TV seating distances (use tv-viewing-distance) or lens-shift/keystone geometry; zoom lenses have a throw-ratio range, so run the calculator at both ends.","inputs":[{"name":"throw_ratio","label":"Throw ratio","type":"number","required":true,"min":0.1,"max":20,"description":"Lens throw ratio = throw distance / image width (e.g. 1.5 means 1.5 m of distance per metre of width; 0.25 for an ultra-short-throw).","example":1.5},{"name":"screen_width_m","label":"Image width","type":"number","unit":"m","required":false,"max":100,"exclusive_min":0,"description":"Desired image width. Give this to get the throw distance (takes precedence over throw_distance_m).","example":2},{"name":"throw_distance_m","label":"Throw distance","type":"number","unit":"m","required":false,"max":200,"exclusive_min":0,"description":"Lens-to-screen distance. Give this alone to get the image size; with the width it also yields the throw ratio the room needs.","example":3},{"name":"aspect_ratio","label":"Aspect ratio","type":"enum","required":false,"default":"16:9","values":[{"value":"16:9","label":"16:9 (HDTV, most projectors)","aliases":["16x9","1.78:1"]},{"value":"16:10","label":"16:10 (WUXGA)","aliases":["16x10"]},{"value":"4:3","label":"4:3 (XGA)","aliases":["1.33:1"]},{"value":"2.35:1","label":"2.35:1 CinemaScope","aliases":["cinemascope","2.39:1","scope"]}],"description":"Width-to-height ratio of the screen or image.","example":"16:9"}],"outputs":[{"name":"throw_distance_m","label":"Throw distance","type":"number","unit":"m","decimals":3,"description":"Lens to screen = throw_ratio × width."},{"name":"throw_distance_ft","label":"Throw distance","type":"number","unit":"ft","decimals":2,"description":"Same distance in feet."},{"name":"screen_width_m","label":"Image width","type":"number","unit":"m","decimals":3,"description":"Projected image width."},{"name":"screen_height_m","label":"Image height","type":"number","unit":"m","decimals":3,"description":"width / aspect ratio."},{"name":"screen_diagonal_m","label":"Image diagonal","type":"number","unit":"m","decimals":3,"description":"√(width² + height²)."},{"name":"screen_diagonal_in","label":"Image diagonal","type":"number","unit":"in","decimals":1,"description":"Diagonal in inches, as screens are sold."},{"name":"required_throw_ratio","label":"Throw ratio needed","type":"number","decimals":3,"description":"throw_distance_m / screen_width_m when both are given, to compare with the lens."},{"name":"throw_type","label":"Lens class","type":"string","decimals":4,"description":"Ultra short throw (<0.4), short throw (0.4–1), standard (1–2) or long throw (>2)."}],"input_schema":{"type":"object","properties":{"throw_ratio":{"description":"Lens throw ratio = throw distance / image width (e.g. 1.5 means 1.5 m of distance per metre of width; 0.25 for an ultra-short-throw).","type":"number","minimum":0.1,"maximum":20,"examples":[1.5]},"screen_width_m":{"description":"Desired image width. Give this to get the throw distance (takes precedence over throw_distance_m). Unit: m.","type":"number","maximum":100,"exclusiveMinimum":0,"examples":[2],"x-unit":"m"},"throw_distance_m":{"description":"Lens-to-screen distance. Give this alone to get the image size; with the width it also yields the throw ratio the room needs. Unit: m.","type":"number","maximum":200,"exclusiveMinimum":0,"examples":[3],"x-unit":"m"},"aspect_ratio":{"description":"Width-to-height ratio of the screen or image.","type":"string","enum":["16:9","16:10","4:3","2.35:1"],"default":"16:9","examples":["16:9"]}},"additionalProperties":false,"required":["throw_ratio"]},"output_schema":{"type":"object","properties":{"throw_distance_m":{"description":"Lens to screen = throw_ratio × width. Unit: m.","type":"number","x-unit":"m"},"throw_distance_ft":{"description":"Same distance in feet. Unit: ft.","type":"number","x-unit":"ft"},"screen_width_m":{"description":"Projected image width. Unit: m.","type":"number","x-unit":"m"},"screen_height_m":{"description":"width / aspect ratio. Unit: m.","type":"number","x-unit":"m"},"screen_diagonal_m":{"description":"√(width² + height²). Unit: m.","type":"number","x-unit":"m"},"screen_diagonal_in":{"description":"Diagonal in inches, as screens are sold. Unit: in.","type":"number","x-unit":"in"},"required_throw_ratio":{"description":"throw_distance_m / screen_width_m when both are given, to compare with the lens.","type":"number"},"throw_type":{"description":"Ultra short throw (<0.4), short throw (0.4–1), standard (1–2) or long throw (>2).","type":"string"}}},"formula":"throw_ratio = distance / width; distance = throw_ratio × width; width = distance / throw_ratio; height = width / aspect; diagonal = √(width² + height²); 1 m = 39.3701 in","method":"Throw ratio is measured from the lens to the screen surface; for zoom lenses use the minimum and maximum ratios from the data sheet. Ultra-short-throw projectors quote the ratio from the lens exit, typically 20–40 cm behind the front of the unit.","sources":[{"name":"Throw (projector) – throw ratio definition (Wikipedia)","url":"https://en.wikipedia.org/wiki/Throw_(projector)","type":"reference","retrieved_at":"2026-09-24"},{"name":"Projector Central – Projection calculator (throw distance)","url":"https://www.projectorcentral.com/projection-calculator-pro.cfm","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":"Throw ratio 1.5, 2 m wide 16:9 image","inputs":{"throw_ratio":1.5,"screen_width_m":2},"expected":{"throw_distance_m":3,"throw_distance_ft":9.84,"screen_width_m":2,"screen_height_m":1.125,"screen_diagonal_m":2.295,"screen_diagonal_in":90.3,"throw_type":"Standard throw"},"url":"https://tttkmbb.com/api/v1/calculate/projector-throw?throw_ratio=1.5&screen_width_m=2"},{"name":"Throw ratio 1.2 at 4 m, 16:9","inputs":{"throw_ratio":1.2,"throw_distance_m":4},"expected":{"throw_distance_m":4,"screen_width_m":3.333,"screen_height_m":1.875,"screen_diagonal_m":3.824,"screen_diagonal_in":150.6},"url":"https://tttkmbb.com/api/v1/calculate/projector-throw?throw_ratio=1.2&throw_distance_m=4"}],"faq":[{"q":"Where is the throw ratio on a spec sheet?","a":"Usually as a range such as '1.32–1.72:1' for zoom lenses; the first number is the widest image from a given distance, the second the most zoomed-in."},{"q":"Does the ratio use width or diagonal?","a":"Width. Distances quoted per inch of diagonal depend on the aspect ratio, which is why this calculator asks for it."}],"tags":["projector throw distance","throw ratio calculator","projector screen size","how far projector from screen","short throw projector"],"related":[{"calculator_id":"tv-viewing-distance","reason":"Seating distance for the resulting image size."},{"calculator_id":"aspect-ratio","reason":"Image dimensions from a ratio."},{"calculator_id":"screen-ppi","reason":"Pixel density of a display of that size."}],"links":{"html":"https://tttkmbb.com/everyday/projector-throw","markdown":"https://tttkmbb.com/everyday/projector-throw.md","json":"https://tttkmbb.com/everyday/projector-throw.json","api":"https://tttkmbb.com/api/v1/calculate/projector-throw","schema":"https://tttkmbb.com/api/v1/calculators/projector-throw","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:44:51Z"}