From Melvor Idle
This page is out of date (v1.1.2).

Template for all the time modifiers for mastery. Splitting off since it's now used for both Mastery and Summoning pages.

These values are sourced from the masteryModifiedInterval() function within each skill's class definition.

Skill Seconds per Action
Firemaking 60% of the log's base burn interval
Cooking 85% of the recipe's base cooking interval
Smithing 1.7
Fletching 1.3
Crafting 1.65
Runecrafting 1.7
Herblore 1.7
Summoning 4.85