The Annapurna Base Camp trek is a 115 km (72 mi) round trip from the trailhead and can be accomplished within 7 to 11 days depending on which route you traverse. Most Annapurna base camp itineraries allow 7 days to reach the base camp and 3 days to get back down, again depending on the route. You will be spending the evening, the entire night and the early morning at the base camp before retracing your steps back. It means that you will be at Annapurna base camp for at least 18 to 20 hours.