How this calculator works
Each character contributes a threshold for easy, medium, hard and deadly encounters at their level. Adding those thresholds across the party gives four party totals. On the monster side, every challenge rating has an XP value; sum the XP of all monsters, then multiply by a factor that makes larger groups more dangerous than the sum of their parts. The adjusted XP is compared with the party totals to place the encounter in a band. The multiplier is used only to judge difficulty: characters still earn the unadjusted base XP. For very small parties (fewer than three characters) the rules shift the multiplier one band up, and for parties of six or more they shift it one band down.
Formula
party threshold for a band = sum of each character's threshold at their level. base XP = sum over monster groups of count x XP for the challenge rating. multiplier depends on the total number of monsters: 1 monster x1, 2 x1.5, 3 to 6 x2, 7 to 10 x2.5, 11 to 14 x3, 15 or more x4. adjusted XP = base XP x multiplier. The difficulty is the highest band whose threshold the adjusted XP reaches.
Worked example
Four level 5 characters have easy, medium, hard and deadly totals of 1,000, 2,000, 3,000 and 4,400 XP. Four CR 2 monsters are worth 450 XP each, so the base is 1,800 XP. Four monsters use a x2 multiplier, giving 3,600 adjusted XP, which lands in the hard band. A single CR 5 monster worth 1,800 XP against four level 3 characters reaches their 1,600 XP deadly threshold, so that fight is deadly even though its XP is lower.
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Frequently asked questions
Does the party earn the adjusted XP?
No. The multiplier is a difficulty gauge only. Award the base monster XP, 1,800 in the four CR 2 example, not the 3,600 adjusted figure.
What changed in the 2024 rules?
The 2024 revision replaced the four bands and the monster-count multiplier with three tiers and a simpler budget. This page follows the 2014 fifth edition rules, which remain the most widely used encounter-building tables.
Why does the multiplier go down for large parties?
A group of six or more characters has more actions and can focus fire, so the same monsters are less dangerous than the raw multiplier suggests. The rules lower the multiplier by one band for those parties, with a minimum of x1.
What about terrain, magic items and surprise?
The XP budget assumes a straightforward fight in neutral terrain. Difficult terrain, a well-prepared ambush or a monster that cannot be reached can push an encounter up a band, while a chokepoint or a party with strong magic items can push it down. Treat the result as a starting point and adjust for the table.