Consulting the Codex…
RS3 · XP Calculator
Work out the XP between any two levels for any RS3 skill — plus how far you are from 99, the skill cap, and 200M.
Level 99 in a standard RuneScape 3 skill is 13,034,431 XP. Invention is the exception — level 99 Invention is 36,073,511 XP because it uses its own experience curve.
Level 120 in a standard RS3 skill is 104,273,167 XP. For Invention, level 120 is 80,618,654 XP.
The XP cap for any single RS3 skill is 200,000,000 (200M) XP, which is well beyond level 120.
Level 92 is 6,517,253 XP and level 99 is 13,034,431 XP, so 92 to 99 is 6,517,178 XP — roughly half of a 99, since each level is about 10% more XP than the last.
XP curves and skill icons courtesy of the RuneScape Wiki (CC BY-NC-SA 3.0).