Question

If Celesteela uses Heavy Slam (move) vs Kartana how high the ratio will be?

Answer 1

Heavy slam works like this:

User's weight / Target's weight

If the use is 5 times heavier or more, it will do 120 base power which is the maximum.

4 times = 100
3 times = 80
2 times = 60
1 times= 40 (minimum damage)

A gastly will do 40 base power if it was able to learn heavy slam.

Edit: Don't forget that it's a steel type physical attack. So physical stats and the target's type matters.

Answer 2

Heavy Slam's maximum power: 120, if that's what you want

Answer 3

>252+ Atk Celesteela Heavy Slam (120 BP) vs. 0 HP / 0 Def Kartana: 72-84 (27.7 - 32.4%) -- guaranteed 4HKO

Source: Damage Calculator

Comments

I think the asker wanted the base power for Heavy Slam if dealing with a Kartana. Not some kind of Damge calculations.