Minecraft wiki entry for Jumping, associated text: Jumping was one of the first transportation mechanics added.
The longest possible distance a player can jump without effects is over 9 blocks, by sprint-jumping out of a 2-block-high ice corridor.
The longest possible distance a player can jump with obtainable effects in survival is over 11 blocks. by using Potion of leaping, Swiftness and Slow falling combined with soul speed III boots on soul sand.
The longest possible distance a player can jump without effects or ice is 5 blocks by just sprinting.