{"uid":"cap_k1U9-yXJGnpUkdFz0h1mY","slug":"aviation-apis-great-circle-distance-e02586d6","name":"Aviation APIs Great Circle Distance","description":"Calculates the shortest distance between two points on Earth using great-circle math.","url":"https://aviationapis.com/great-circle-distance","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"to":{"type":"object","required":["lat","lon"],"properties":{"lat":{"type":"number","description":"Latitude in decimal degrees (-90..90)"},"lon":{"type":"number","description":"Longitude in decimal degrees (-180..180)"}}},"from":{"type":"object","required":["lat","lon"],"properties":{"lat":{"type":"number","description":"Latitude in decimal degrees (-90..90)"},"lon":{"type":"number","description":"Longitude in decimal degrees (-180..180)"}}},"groundspeed_kt":{"type":"number","description":"Optional ground speed (kt) to compute estimated time en route"}}},"responseSchema":{"type":"json","example":{"to":{"lat":40.6398,"lon":-73.7789},"from":{"lat":37.6188,"lon":-122.375},"ete_hms":"04:57:56","distance_km":4138.3,"distance_nm":2234.5,"distance_sm":2571.5,"ete_minutes":297.9,"groundspeed_kt":450,"final_bearing_deg":119.6,"initial_bearing_deg":69.8}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","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":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_Qqa1kap7XqBWU2EEWHY8p","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates the great circle distance and bearing between two geographic coordinates, optionally computing estimated time en route given a ground speed.","exampleAgentPrompt":"What's the great circle distance and estimated flight time from SFO (lat 37.6188, lon -122.375) to JFK (lat 40.6398, lon -73.7789) at a ground speed of 450 knots, including the initial and final bearings?","exampleUseCases":null,"resultDescription":"Returns a JSON object with the great circle distance in kilometers, nautical miles, and statute miles; initial and final bearings in degrees; and optionally estimated time en route in both HH:MM:SS format and decimal minutes if a ground speed was provided.","failureModes":["Missing required lat/lon fields returns a 400-level error","Latitude out of range (-90 to 90) or longitude out of range (-180 to 180) causes validation failure","Negative or zero ground speed may produce nonsensical ETE values","Payment failure via x402 protocol returns 402 Payment Required"],"whenToPreferThis":"Use this endpoint when you need aviation-grade great circle distance and bearing calculations between two geographic points, especially when nautical miles and estimated time en route at a given knot speed are required. Prefer over generic geodesic calculators when the output needs to include initial/final bearings and ETE in HMS format suitable for flight planning.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:45:42.248Z","isFirstParty":false}