Help with finding a balanced damage formula

So In my game you can do damage with magic attacks. Though, I’m having trouble finding a good formula to calculate damage.

There are a couple things that need incorporated into the formula:

-Base Damage (The base amount of damage the attack does)
-Player Level (Ranging from 1 - 100)
-Damage Multiplier (Multiplies Damage)
-Accessory Bonus (Increases Base Damage)
-TimeHeld (Amount of time user was charging the attack, usually max is 5 seconds)

For reference, a max level player should be able to 1 shot or easily 2 shot a level 1. Another thing, time held should also have a big impact on the calculated damage.
If anybody has ever made a formula for calculating damage, your advice would be great. :hear_no_evil:

I think this should work
Damage = ((BaseDamage + AccessoryBonus) * ((PlayerLevel / 1.5) + DamageMultiplier))
You will have to make the variables yourself though.

Thank you. I’ll try rearranging it till I like it. And i just realized i forgot one of the most important things, TimeHeld.

if you want time held, use this
Damage = ((BaseDamage + AccessoryBonus) * ((PlayerLevel / 1.5) + DamageMultiplier + (TimeHeld / 1.5)))

Feel free to change the amounts divided or multiplied by.