Encounter Calculator

Encounter Calculator (Aldium version)

Party: Enter the Qty and ECL of characters in the Party.
Note: For PHB races, ECL = Class Level
XP Awards (per character) Monsters: Enter the Qty and CR of each opponent the Party faces.
Note: CR's may be entered as fractions.
Qty ECL CR Based Difficulty Based Qty CR
Uniform XP per Character Treasure Value

Spotting Distance by Terrain Type (reference):
Effective Party Level Encounter Level Difficulty
Average Party Level Difficulty Factor Advice to Party

XP Awards (per character): Four different versions have been offered depending upon which method the DM chooses to use.
CR based Individual XP (listed per ECL) uses the rules in the 3.5 DMG and 3.0 FRCS to determine XP based on the actual character levels (treated as a minimum of 3), individual opponent CR's, and the Qty in the party. This grants higher XP to lower level participants, allowing them to catch up to their higher level comrades. CR based Uniform XP uses the rules in the 3.0 DMG to determine XP based on Average Party Level (treated as a minimum of 3), individual opponent CR's, and the Qty in the Party. Analysis proves this only really works for a party of four with the same ECL's. Difficulty based Individual XP uses the guidelines that it takes 13 1/3 typical (difficulty factor 0) encounters to advance a level. However, using this method, differing level companions will never catch up in either XP or level. In my opinion, this method adheres most closely to the spirit of the rules. Difficulty based Uniform XP uses the guidelines that 13 1/3 typical encounters to advance a level. However, because Average Party level is used as a multiplier instead of the individual character levels, differing level companions will eventually catch up in level (but not XP).
This is the method I recommended.
Average Party Level is the numerical average (arithmetic mean) of the levels (or ECL's) of the party members. Effective Party Level is calculated using the same method as to calculate Encounter Level. This party should be equivalent to four characters of the effective party level.