How many boxes will i need for a area 39 by 15?

Please go to the Lowe's webpage for Restoration Oak flooring at https://www.lowes.com/pd/QuickStep-Studio-Restoration-Oak-7-48-in-W-x-3-93-ft-L-Embossed-Wood-Plank-Laminate-Flooring/1000397289. Scroll down to the Projects,Tios & Services, click on Flooring Calculator. Enter your room dimensions to get your square feet. Go back to the first webpage for your flooring, then scroll down and click on Specifications. This particular flooring states there are 19.63 square feet per carton. At this point you can calculate how many boxes you will need for your install. Don't forget to add a little extra. If you need further assistance, please contact your local Lowe's flooring specialist. GerrieM