Shipping cost surcharge for long item

Hello everybody,

I need to add a surcharge shipping cost for long items.

How can I do that?

I’d like to add a shipping surcharge rate when the product is longer than 100 cm.

I understood I have to create a surcharge shipping type in the shipping cost management and that I have to calculate the rate based on „Calculation“.

Then in the Calculations field I wrote: "If (d.length >100,10,0) because I want to add 10 euro to the standard shipping cost when the product is longer than 100 cm.,

but this didn’t work at the checkout then.

What have I made wrong?