Read laptop-sleeve dimensions without confusing the inside

The short answer

Screen diagonal is only a shortcut. Check the exact laptop model, any hard shell you use and the sleeve opening.

Make the check

Measure the device. Record the closed laptop width, depth and thickness, including any attached shell. Keep all three measurements in the same units as the listing.
Find the internal specification. Look for “laptop compartment” rather than the overall product size. Thule publishes both for the cited Koya sleeve, so there is no need to infer the internal space from the outside.
Compare each axis. All three dimensions must be compatible. If a number is missing or clearance is marginal, ask the maker about the exact model rather than forcing a tight fit.
Check how it opens. A usable fit includes getting the laptop through the opening without scraping or compressing it. An indoor fit check should respect the seller's return conditions.

A worked example

Thule lists the cited Koya laptop compartment as 14.2 × 9.9 × 0.7 inches and the exterior as 15.4 × 1.2 × 10.6 inches. These describe different things and the axis order differs in presentation. Label each axis before comparing, and recheck the current model page before ordering.

What to watch out for

A “16-inch” laptop can have a different body from another 16-inch model.
A protective shell changes device dimensions.
Do not interpret padding or a water-resistant coating as a drop or waterproof guarantee.

Check two separate fits

First compare the closed laptop to the sleeve’s usable compartment. Then compare the sleeve’s exterior to the backpack or briefcase opening. Record an attached hard shell in the laptop measurement rather than assuming it does not matter. If the listing omits internal depth or its axes are unclear, ask the maker for the exact device model. A larger advertised screen-size category is not a substitute for those missing measurements.

A local check for this task

Compare the measured exterior with the usable interior, including a chosen clearance.

Sources and evidence

Thule Koya | Thule | United States (read November 7, 2026)
FAQ (read November 7, 2026)

Use the local-only measurement and header workbench. A numerical check does not replace the source instructions or a physical fit check.

Common checks

Can I use the outside sleeve dimensions as its capacity?

No. Padding, seams and the closure take space. Use the published compartment dimensions or ask the manufacturer.

Published November 7, 2026. Sources last read November 7, 2026. Send a correction.