KALLAX Shelf unit, white, 30 1/8x30 1/8 "
+11¼″ margin
Will fit in an ?
No, it won't fit.
It will not fit in this setup: BILLY Bookcase, black oak effect, 31 1/2x11x79 1/2 " is too large for an Aiways U5 2021 with seats up.
Fit Details
With seats up, This package will not fit in this setup. The blocker is opening width, and you're short by 21⅞″ even with diagonal loading. We're about 95% confident in this estimate.
BILLY Bookcase, black oak effect, 31 1/2x11x79 1/2 "
Box: 81¼″ × 11¾″ × 5″ · 86 lb 15 oz
Based on IKEA US (United States).
Package dimensions last checked and updated on Aug 06, 2026
Package
Status
Limiting factor
Best orientation
Package #1
81¼″ × 11¾″ × 5″
Status:21⅞″ short
Limited by
Limiting factor:Opening width
Best orientation:Diagonal
Vehicle limits
Opening width / height
39¾″ / 29⅞″
Cargo width / height
40⅛″ / 30¾″
Cargo length seats up / down
41″ / 73¼″
Loading sill height
29⅞″
Aiways U5 2021
Measurements last checked and updated on Sep 01, 2026
Helpful tips
Use these loading tips to improve your chances of fitting BILLY Bookcase, black oak effect, 31 1/2x11x79 1/2 " in Aiways U5 2021.
Optimize opening width
Keep the narrow edge leading while entering the opening.
Load diagonally first
Load diagonally first, then straighten once inside.
Try fitting alternatives
Check the Similar items that fit section for safer alternatives.
Alternatives that fit in Aiways U5 2021
Ranked by fit margin and package-dimension similarity. This improves as we index more items.
About the Aiways U5 2021 boot
The U5 is one of the more forgiving boots to load. The opening measures 39¾″ wide by 29⅞″ tall, the floor runs 41″ with the seats up, and folding the bench takes it to 73¼″, a gain of 32¼″. Width holds at 40⅛″ at the narrowest point, so the space stays close to square. The sill sits 29⅞″ up with a ¾″ drop to the floor, near enough level to slide heavy boxes straight off the bumper. Long flat cartons suit it once the seats are down. Load those first, then pack around them.
About the BILLY Bookcase, black oak effect, 31 1/2x11x79 1/2 " package
The BILLY bookcase comes as a single long, flat box: 81¼″ × 11¾″ × 5″ and 86 lb 15 oz. It is the length that catches you out, not the weight on its own. That long panel wants a flat floor, which on most cars means folding the rear seats first. The board is rigid and will not flex around a wheel arch or a short boot, so it has to lie straight. An estate, a folded-seat hatchback, or an SUV takes it comfortably. Load it long-edge first, keep it flat, and guard the corners, because a knock at this weight cracks the edge.
Frequently asked questions
Find quick answers about fit for BILLY Bookcase, black oak effect, 31 1/2x11x79 1/2 " in Aiways U5 2021, including seats up vs seats down, limiting factor, best orientation, and package-by-package margins.
Will BILLY Bookcase, black oak effect, 31 1/2x11x79 1/2 " fit in Aiways U5 2021?
No. With seats up, it is short by 21⅞″ at Opening width, even with diagonal loading.
What is the tightest part?
The limiting factor is Opening width, with -21⅞″ margin in seats up.
What should I do instead?
Use the Helpful tips & alternatives section to choose a smaller item, different orientation, or split-load plan.
Is the trunk opening the issue?
Yes. The tightest constraint is at the opening (Opening width) with -21⅞″ margin.
How tight is this fit?
This result is in the clear no-fit band (-21⅞″ at Opening width).
Does it fit with seats up or seats down?
Seats up: No (-21⅞″). Seats down: No (-2¾″). Default selection follows YES > MAYBE > NO.
Why does it not fit?
The blocker is Opening width. The worst margin is -21⅞″ in seats up, so clearance is below the required buffer.
Can I load it diagonally?
Yes, diagonal is the best orientation for this check, with -21⅞″ around the limiting point.
Which loading orientation works best?
Diagonal is the best orientation for this result in seats up.
How confident is this result?
Confidence is 95 out of 100 based on available dimensions and margin tightness.