fixed shipping costs per packet

Hey,

I am building a WooCommerce Shop and need to have fixed shipping prices per packet.
Therefore I wrote a formula in the product->shipping->costs field.
The amount of packages is: [qty]*0.012/23 and then I would muliply this with my customers fixed shipping price per package but if the result is 3.21 it should be rounded up to 4 shipping packages. I cant find a function in the documentation that does this.
Also when the amount is >= 10.000 then the price should always be another fixed price till >= 18.500 then another fixed price.

I also looked into some plugins but did not find one that can handle this.