Combat level

A player's, monster's, or character's combat level indicates the difficulty in defeating him, her, or it in combat. Levels that are lower than yours display green, levels that are equal to yours display yellow , and levels that are higher than yours display red. Relatively few players, monsters, or NPCs have a combat level over 100.

Normally, aggressive NPC's stop attacking you when you reach higher than double their combat level. There are exceptions, however - for example, any monsters in the wilderness will be aggressive no matter what your combat level.

Monsters with a higher combat level than a player, cannot be attacked by using a left mouse click. Instead, players need to right click and select the attack monster option. So, to be able to attack a Blue Dragon with combat level 111 with a simple left click, a player needs a combat level of at least 111.

All new players start out at combat level 3, and the maximum level for RuneScape 2 is 126, while in RuneScape Classic, it is 123.

Simply

 * 1) Take your prayer level and divide it by two and round down (For example, if your prayer level is 43, dividing by two and rounding down gives you 21)
 * 2) Add this to your hitpoints and defence levels and divide the result by 4. This is your base combat level.  (For example, if your hitpoints is 60, defence is 41 and prayer is 93 you should end up with 37.95)
 * 3) Add your strength and attack together and multiply by 0.325. Add this to your base combat level and you should have your (melee) combat level.
 * 4) If your magic or fletching level is exceptionally higher than your attack and strength, carry on - in the calculation noted below magic is used, but if your range is exceptionally higher, use that instead in all cases
 * 5) Divide your magic level by 7 and round down, and then add your magic level again to this (For example, if your magic level is 13, you should end up with 24).
 * 6) Multiply this by 0.325 and add the result to your base combat level calculated above, and you should have your magic combat level.

Wiki Combat Calculator
The Combat template contains the combat formula described above. It also contains some examples. If you want to experiment you can edit this section and use the Show preview button to activate the template. After reloading, please use the Back button of the web browser to leave the web page unchanged.

The combat level is given for each of the three combat types. In the table that is the right most column. See the earlier text for the background.

Comments
Combat level is the only in-game visible parameter that players have to evealuate another player. High combat levels do not always accurately describe a players' capabilities in other skills. There are players with maximum combat that have very low levels in other skills and there are pure skillers with no combat levels and very high non-combat skills. Yet, there is a reasonable change that a high combat level also implies a decent skill level and a reasonable knowledge of the game.

A more complicated assesment is in the trustworthiness of a player in trades. Some players place higher trust in higher combat level players as they have more to lose when they get banned after being reported for illegal trading practices. Yet, as a general rule, players should distrust other players that they do not know in person.