Natural mob spawns happen within 15 x 15 chunks around the player, or 240 x 240 blocks. Multiple players will have their own spawning area, so mobs will spawn within the distance relative to each player.

How far away do you need to be for mobs to spawn?

Mobs won’t spawn closer than 24 blocks. They won’t move around when farther than 32 blocks. Those are the only rules you need to know for a grinder that relies on mobs walking around.

Where do mobs spawn in Minecraft bedrock?

Most animals spawn within chunks when they are generated. Mobs spawn naturally within a square group of chunks centered on the player, 15×15 chunks (240×240 blocks). When there are multiple players, mobs can spawn within the given distance of any of them.