Teespring calculates your shipping fees based on the items that you're ordering. Items with different weights have different prices ranging from $1.00 to $6.99. Your shipping total depends on how many items you're ordering and the type of item it is.
You can find all of the shipping rates for the various item types on the Shipping Information page. While at checkout, you'll be able to choose between Standard and Rush Shipping. Rush shipping requires an additional charge of $3.99 on top of the standard shipping price.
Sometimes you can find Teespring promos for free shipping on your entire order.