IKEA sells a drawer for its 18-inch SEKTION cabinet. The inside of that drawer is 16½ inches wide. The 15-inch version is 13½ inside, the 24-inch is 22½. In every case the drawer gives up 1½ inches to the box walls and the slides, and the number on the cabinet is the number most people type into a shopping search.
That gap is where organizers go back in the box.
The three numbers, and where each one hides
Inside width. Usable depth. Clear height with the drawer closed. Write all three down before opening a product page, because product pages list the organizer's outside dimensions and nothing else.
Width is the one everyone gets wrong, so start there. Cabinet makers sell in 3-inch steps. KraftMaid's size chart lists base cabinets from 6 to 48 inches wide in 3-inch increments, 24 inches deep, 34½ tall. Those are cabinet widths. The drawer box inside is narrower by the thickness of two box sides plus the slide hardware. A cabinet-shop guide from CKF puts side-mount slides at "about ½ inch per side, so subtract roughly 1 inch from the opening width," and undermount slides at about ¼ inch per side. Add the box sides and you land at the 1½ inches IKEA publishes.
Depth is the quieter surprise. A 24-inch-deep base cabinet does not hold a 24-inch drawer. IKEA's MAXIMERA drawers for the 24-inch-deep frame are 21⅜ inches deep inside. CKF's guide says "drawer box depth typically lands between 20 and 22 inches in a standard base cabinet." An organizer sold as "fits 24-inch drawers" is describing the cabinet, not the box.
Height is measured wrong more than it is measured. The IKEA medium drawer is 5⅝ inches tall inside, but the number that decides whether a tiered tray fits is the clearance under the cabinet rail or the drawer above it when the drawer is shut. Measure with the drawer closed, tape in from the top, and take the smaller of the two figures.
Which of the three did you skip last time? For most people it is depth.
A fit check on two trays, using the makers' own numbers
Take the IKEA 18-inch medium drawer: 16½ wide, 21⅜ deep, 5⅝ tall inside.
Joseph Joseph publishes its DrawerStore Compact Tiered Cutlery Organizer at W5 × D15.6 × H2.4 inches and says it "fits drawers with a minimum height of 9 cm (3.5")." Width 5 against 16½: fits, with 11½ inches beside it. Depth 15.6 against 21⅜: fits, with almost 6 inches of dead space behind it. Height: the body is 2.4 inches, but the number to compare is the maker’s minimum drawer height of 3.5 inches against the 5⅝-inch drawer. Met, with room to spare.
YouCopia lists its DrawerFit Sliding Drawer Bin at 15.0–23.7 inches deep (it expands front to back), 7.1 wide and 2.7 tall, and says its locking teeth keep the bin extended “to sit on top of drawer frame.” That last part changes the arithmetic: the bin rides on the drawer’s frame above whatever sits on the bottom, so it is not a footprint you place beside the tray. Its 7.1-inch width is taken at the frame, and whether the closed drawer clears a 2.7-inch bin riding on the frame is a clearance question the maker’s page does not answer. The size check marks frame-supported models “more to check” for exactly this reason.
On the width numbers alone, tray plus bin come to 12.1 inches against 16½: both clear the 18-inch drawer, and the tray clears on its own in every direction. Move the pair to the 15-inch drawer (13½ inside) and 12.1 still clears by 1.4 inches. Now imagine a drawer someone measured at the front as “15 inches” that is really a 13½-inch opening minus 1 inch of side-mount slides: 12.5 against 12.1 clears by four tenths of an inch. That is not a margin to order on without the tape, and it still says nothing about the bin’s frame clearance.
Where the plan fails, in the order it usually fails
The front is measured instead of the inside. The drawer front on an 18-inch cabinet is often 17¾ or the full 18. The box behind it is 16½ or less. CKF's guide says it in one line: "Always measure the opening itself, not the existing drawer box or front."
The cabinet depth is used as the drawer depth. A fixed 22-inch tray bought for a "24-inch drawer" does not go in a 21⅜ box. The expandable trays exist because of this exact mistake, and their minimum length matters as much as their maximum: a 15-to-23.7 expander cannot shrink into a 14-inch bathroom drawer.
Height is taken with the drawer open. Open, there is nothing above the drawer. Closed, the rail is there. A tray whose maker states a 3.5-inch minimum drawer height does not meet that requirement in a drawer with 3¼ inches of closed clearance, however small the tray body looks. The maker’s number, not the body height, is the one to compare.
The organizer is chosen before the drawer is measured. This is the one that costs money, and it is the reason the measure-a-drawer guide is the first page on this site instead of a product list. This site’s drawer size check lets you save the three numbers once and test any organizer’s listed dimensions against them in the browser, without an account and without a shopping link.
What to write on the sticky note
Inside width to the nearest ⅛ inch. Depth from the inside of the front to the inside of the back. Clear height, drawer closed. Then, for any organizer: its width, its depth (both ends of the range if it expands), its height, and any minimum drawer height the maker prints.
If the maker does not print a dimension, that is the answer. Skip it.
Sources
- IKEA, MAXIMERA drawer, medium, white, 18x24" (art. 002.656.65): frame 18 × 24", inside 16½ × 21⅜ × 5⅝". https://www.ikea.com/us/en/p/maximera-drawer-medium-white-00265665/ (accessed 2026-09-09)
- IKEA, MAXIMERA drawer, medium, white, 15x24" (art. 002.656.70): inside 13½ × 21⅜ × 5⅝". https://www.ikea.com/us/en/p/maximera-drawer-medium-white-00265670/ (accessed 2026-09-09)
- IKEA, MAXIMERA drawer, medium, white, 24x24" (art. 802.656.66): inside 22½ × 21⅜ × 5⅝", max load 55 lb. https://www.ikea.com/us/en/p/maximera-drawer-medium-white-80265666/ (accessed 2026-09-09)
- KraftMaid, "What Are Standard Kitchen Cabinet Sizes?": base cabinets 34½" tall, 24" deep, widths 6"-48" in 3" increments. https://www.kraftmaid.com/kraftmaid/kitchen-cabinet-sizes (accessed 2026-09-09)
- CKF Co., "Kitchen Drawer Sizes Guide": box depth 20-22", side-mount slides ~½" per side, "measure the opening itself." https://www.ckfco.com/feeds/blog/kitchen-drawer-sizes (accessed 2026-09-09)
- Joseph Joseph US, DrawerStore Compact Tiered Cutlery Organizer: H2.4 × W5 × D15.6 in, "minimum height of 9 cm (3.5")." https://us.josephjoseph.com/products/drawerstore-compact-tiered-cutlery-organizer-stone (accessed 2026-09-09)
- YouCopia, DrawerFit® Sliding Drawer Bin with SlideLock™: "Measures 15.0"-23.7" D x 7.1" W x 2.7" H" and "Locking teeth keep bin extended to sit on top of drawer frame." https://youcopia.com/products/drawerfit-sliding-drawer-bin (accessed 2026-09-09)
- Inch & Drawer, How to Measure a Drawer for an Organizer and the Drawer Organizer Size Check (own site).