It depends completely on what logs you are using and how much time you spend in Runescape per day.
this will entirely depend on how many hours a day you plan on training with these and what your current firemaking level is.
It all depends what level your Firemaking is. lets say your Firemaking is 58 (Just high enough to burn eucalyptus logs) you would have to burn just over 66,000 eucalyptus logs.
96,551. :) good luck
Really depends on what skill. For mining, agility, and firemaking, you want a penance horn for double xp.
train...
That's best consulted at an online skill calculator, such as the ones available at salmoneus.net, or runescape.wikia.com.
You would need to chop approximately 94524 maple logs in order to advance from level 60 to level 99 in firemaking. ---------------- Fact: Did you know by the time you get level 95 in a skill you will have to get all the experience you acquired to get to level 95 again in order to get level 99?
One maple log on RuneScape will grant you 135 Firemaking experience when burned. You need 11,824,010 experience points to advance from level 75 to level 99 in a skill. 11,824,010 divided by 135 equals 87,585.25926.Therefore, you will need to burn 87,586 maple logs to advance from level 75 to level 99 in Firemaking (assuming you receive no experience bonuses).
Firemaking
For non-members, burn yews. For members, there are higher-level logs; you can also do the minigame "All Fired Up" for some fast experience.
Getting firemaking from level 60 to level 99 using willows will require about 134954 willow logs if using bonfires. It would cost you about 2.8m worth of willow logs or more if using the traditional firemaking method. Some money will be earned back with runes, firelighters and ashes from the fire spirits. It will take about three-four weeks if you play at least five hours a day.
Achieve level 50 runecrafting.