Flight Soekarno–Hatta International Airport departs from Jakarta Soekarno–Hatta International Airport at 15:25 and arrives at Singapore Changi Airport at 18:30.
The flighttime is about 2h 05m. The distance travelled ("as the bird flies"): 369 Km. So the average speed is roughly 177 Km.
There is an 1 hour time difference between Jakarta and Singapore
The best month to arrive at Jakarta is November and the most expensive month to fly is September. (Average prices, based on 1846 datapoints.)
We have a lot more statistics for flights KL 4856 and between Jakarta and Singapore.