If you sell through Etsy and ship through Paypal like I do… here’s some quick links I use often. If the buyer did not pay through Paypal you can still use Paypal to ship! Use the ship now link below! I bought a food scale to use at home and it comes very handy. No dragging three kids to the post office! I do all my shipping from home. And if you use something like paypal for shipping, tracking is always included. The rates went up again! See below for current postage rates.
Etsy fees: https://www.etsy.com/help/article/136
Etsy fee calculator: https://etsyrank.com/profit-calculator
Etsy shipping calculator: https://www.etsy.com/shipping/us/price-your-postage
Paypal fee calculator: http://thefeecalculator.com/
Paypal ship now link: https://www.paypal.com/us/cgi-bin/webscr?cmd=_ship-now
Profit calculator: https://craftybase.com/etsy/fee-calculator