Weapon Matchmaking | Dark Souls 3 Wiki

Weapon Level Matchmaking

When summoning a friendly or competitive phantom without using a password, the game defaults to showing you signs of players within specific level and weapon upgrade ranges. The following table below shows the matchmaking ranges for all upgrade levels for both Normal and Somber weapons. Credit to Ratatoskr for his YouTube video All The Weapon Level Ranges In Elden Ring for the following data.

Key for the table: X - A-B/C-D (X is current weapon level, A-B is the lowest to highest matchmaking for Regular weapons, C ~ D is the lowest to highest for Somber weapons)

Notes:

• Weapon Matchmaking is only half of the equation regarding which signs a player will see, and is independent of Rune Level, though both matter equally. For example, a RL 150 player that never upgraded / received an upgraded weapon throughout their playthrough will likely see few if any signs without the use of a password. 
• The Weapon level considered is always the highest the player has ever acquired, whether through upgrading, looting, killing enemies or speaking with NPC's. This level is fixed at the time of acquiring the weapon level, and cannot be lowered by storing/deleting the weapon. In other words, it only goes up and can't be lowered.