Basically I found an egg hatching tutorial and this is the chance script; Im having trouble understanding how rare each rarity actually is. Is there any way to convert these into percentages? ( without changing the code, i just want to have

--[[
    Rarities;
    1K = 25%
    500 = 13%
    300 = 6%
    100 = 3%
    1 = 1%
--]]

Not those exact percentages but something along those lines

local module = {
--Demonic
            ["Common"] = {
        ["Cost"] = 500,
        ["Pets"] = {-- {Weight/Rarity}
            ["Cat"] = {1000},
            ["Dog"] = {1000},
            ["Bunny"] = {300},
            ["Bear"] = {300},
            ["Rare Pet"] = {100},
            ["Unobtainable Pet"] = {1},

        },
            }
            }


return module
--[[
    Rarities;
    1K = Common
    500 = Uncommon
    300 = Uncommon
    100 = Rare
    1 = Extreme
--]]

and here is where the math.random is:

local function ChoosePet()
    local Chance = math.random(1,TotalWeight)
    local Counter = 0
    for i,v in pairs(Pets) do
        Counter = Counter+v[1]
        if Chance <= Counter then
            return i
        end
    end
end

here is the full script in case you need it;

local ProximityPromptService = game:GetService("ProximityPromptService")
local RS = game:GetService("ReplicatedStorage")
local Eggs = require(RS:WaitForChild("Eggs"))
local Data = Eggs[script.Name]
local Cost = Data["Cost"]
local Pets = Data["Pets"]


local Buy = game.Workspace.Eggs.Common
local Cost1 = Buy:WaitForChild("Cost")
local CD = Buy.Buy:WaitForChild("ProximityPrompt")
local CostGUI = Cost1:WaitForChild("Am")
local CostText = CostGUI:WaitForChild("TextLabel")

CostText.Text = Cost.." Coins"

local TotalWeight = 0
for i,v in pairs(Pets) do
    TotalWeight = TotalWeight + v[1]
end

local function ChoosePet()
    local Chance = math.random(1,TotalWeight)
    local Counter = 0
    for i,v in pairs(Pets) do
        Counter = Counter+v[1]
        if Chance <= Counter then
            return i
        end
    end
end

CD.Triggered:Connect(function(Player)
    local Stats = Player:WaitForChild("leaderstats")
    local Coins = Stats:WaitForChild("Coins")
    local open = Player:WaitForChild('OpenValue')
    local got = Player:WaitForChild('GotPet')
    if Coins.Value >= Cost then
        Coins.Value = Coins.Value - Cost
    open.Value = 'Open'
    got.Value = ChoosePet()
    local findpet = Player:WaitForChild('Pets')
    local sqq = findpet:FindFirstChild(got.Value)
     sqq.Value = 'owned'
        wait(5)
    open.Value = 'Close'
    got.Value = ''
    end
end)