The Bag Fit Kit

Buy a bag that fits what you carry: the laptop checked by its own width and height, the liters you can really pack, the weight it will be, and what it costs per carry you will actually make

SatchelBag's tools each answer one question, and on their own they can disagree. What Fits In My Bag counts a laptop as 3 liters, so a laptop "fits" any bag with 3 liters to spare, including bags it cannot enter. A listing's liters are often a box drawn around the outside, walls and lining included. And the Bag Cost-Per-Wear Calculator is only as honest as the number of carries you type in. The Bag Fit Kit puts the site's tools in the order a real purchase happens. It checks the laptop by its own width and height, in its sleeve: a 15.6 inch notebook at 35.8 x 24.2 cm needs a 37.8 x 26.2 cm pocket bare and 39.8 x 28.2 cm in a sleeve, which one of three example bags has. It reads an 18.2 liter listing as 10.3 to 13.9 liters inside, sizes the bag so your fullest day fills 80 percent of it, weighs the carry packed, works cost per wear on four weeks of logged carries (a $240 bag at a hoped $0.31 a wear is $1.15 at the rate actually carried, and needs 312 carries to match an $80 bag), and measures the outside, packed and handles up, for travel. Every figure in the kit is computed by the site's own tools from examples you replace with your own. It states no airline's size limits (it sends you to the airline's page) and makes no medical claims; the one carrying guideline it cites is HealthyChildren.org's 15 percent of a child's body weight, with its source. Included: 7 steps, three printable working pages, a fit and liters reference, a quickstart, and a personalised sheet worked from the figures you enter in the laptop fit, bag capacity and cost-per-wear calculators.

Look inside

Two full pages from the kit, exactly as printed. Click either to read it at full size before you decide.

What is in it

• The Laptop Rule: the laptop checked by its own width and height, bare and in its sleeve, plus 2 cm, against three bags
• The Ceiling Rule: a listing's liters read as a ceiling, and the inside worked at 1 and 2 cm walls
• The Two-Questions Rule: why a volume check passes a laptop that width and height refuse
• The 80 Percent Line: the inside liters your fullest day needs, with a sweater-day check
• The Packed-Weight Rule: the carry and the bag weighed together, and the cited guideline for a child's backpack
• The Logged-Carries Rule: cost per wear on four weeks of logged carries, with care costs and a break-even against a cheaper bag
• The Airline's-Page Rule: the outside measured packed and handles up, against the limit you copy from your airline
• Three working pages: a carry inventory, a bag shortlist and a four-week carry tally
• A fit reference (the pocket each screen size needs, bare and in a sleeve) and a label-to-inside liters table
• A personalised sheet worked from the figures you enter in the laptop fit, bag capacity and cost-per-wear calculators

The kit picks up where the free Laptop Bag Fit Checker leaves off. The checker tells you whether one laptop goes into one bag; the kit measures the laptop in its sleeve, reads a listing's liters as a ceiling (with the Bag Capacity Calculator), shows why a volume check never fits a laptop, sizes the bag to an 80 percent fill line, weighs it packed, works the cost per wearon the carries you actually log, and measures the outside for travel. It states no airline's size limits (check your airline's own page) and makes no medical claims. The worked figures are examples.