About 1,385 nm — roughly 3h 39m in a midsize jet. Nothing live on this exact route this minute. Save the route and we will watch it for you.
Every price on EmpTleg buys the entire aircraft, not a seat.
Singapore to Hong Kong is a different flight with its own aircraft, its own days and its own price: empty legs from Singapore to Hong Kong.
Nobody schedules an empty leg. One shows up here because an operator has an aircraft finishing a trip near Hong Kong and needs it near Singapore — or needs it home, and this direction happens to be the way home. That is why the flight can be a fraction of a full charter, why it can vanish within hours, and why the return direction is a different flight entirely with its own price and its own aircraft. Watching the route beats searching it once.