General

Wow this really had me working again of my lame math skills, but it worked after few attempts
Thanks!

Max Range: {Weapon Multiplier * [(4 * Primary Stat) + Secondary Stat] * [(Attack/100) * (1+Atk%)]} * (1 + TotalDmg%)

It should be noted that while Total Damage can increase your range significantly, it's factored into your actual damage alongside boss damage, so it's true impact on your damage isn't as significant as it may seem based on your range.

True Damage: {Weapon Multiplier * [(4 * Primary Stat) + Secondary Stat] * [(Attack / 100) * (1+Atk%)] } * Skill % * (1 + %Boss + Total Damage%)

Multiply the result from true damage by your average crit multiplier (average of your min and max crit) and then by any final damage buffs you might have for your true damage with crits.

@morrie2: Although this method seems pretty smart, it won't necessarily work. For one thing, people's min and max crit could very greatly, so that can greatly affect range.

Also, at a certain point people just hit cap, and when you hit cap you can have a 10m range but still look like youre doing the same amount of damage as someone with 6-7m range.
In short, the damage calculator provided above should be your best bet.

Weapon Multiplier * ((4 * Primary Stat) + Secondary Stat) * (Attack / 100)

https://ayumilovemaple.wordpress.com/maplestory_calculator_formula/

attack monter with normal attack devide by crit and boom, do this 100 times for more accuracy