Need help with calculating sub total and shipping costs to t-shirt order.

https://www.jotform.com/build/73394155284159

These are the fields you are using to perform calculations:

I have cloned your form, and noticed that the calculation for "Sub total 1(shirts)" is not correct:

Please update it to this:

On regards of "Sub Total 2 (Shipping)", what is the formula? The total quantity from the shirts sizes multiplied by 3? If that is correct, please update the calculation from this:

To this:

Now, on regards of the "Sub total" fields, I noticed that it is not a "form calculation widget", you attempted to update the result into that field through conditions, please delete that field and the conditions.

Finally, rename the "Total" field as "sub-total", and update the calculation, example:

Here is my test form: https://form.jotform.com/80495332426962 

Let us know if you need more help.