How do you measure area rugs?

If the room is square you only need to multiply thelength by the width. For example a room that is 12 ft x 12 ft is 144 square feet.
If you have a room that is an irregular shape, the easiest way is to break the room into sections. An L shaped room can be measured in two sections. Or a part of a room the jets out away can be measured separate and added in.
If you still feel uncomfortable with your measurements, most flooring retailers offer measurements. Often if you buy your flooring from them, they will wave the fee.
Don't forget closets and the necessary 10% for waste.
Bedroom: 144
Closet: 66
Hall: 130
Total: 340 Sq Ft
Add 10% for waste - 340 x 1.1 = 374
You would need 374 total
Take your total and the amount of square footage in the box and divide it into the total. Lets assume your box has 22 square feet.
374 / 22 = 17 boxes
One last point. When you are out shopping for laminate, compare prices by square foot and not the box price. All brands put a different amount into their boxes.

In a perfect world, all measurements would be whole numbers (12x12=144) You may notice that your area most likely wont be in exact feet. An example would be 10 ft 4 inches by 10 ft 4 inches. So how do you convert those pesky inches to feet?

Step 1. Multiply your Feet together: 10x10=100 SQ FT

Step 2. convert your inches to a decimal and add to your total feet: 10 + .04=10.04

Step 3. Multiply together: 10.04 X 10.04= 100.80

Step 4. Divide the decimal amount (inches) by 12: 80/12=6.6

Step 5. Add to your SQ FT to get your total square footage: 100+6.6=106.6 or 6 ft 6 inches

If you don't like this method, you could just round up to whole numbers considering there will be waste involved. I guess it just depends on how accurate you want to be.