File drawer layouts
Lateral vs front to back file drawers
Hanging files can run two ways in a drawer. Front to back, the way most desk drawers work, or lateral, side to side, the way wide office cabinets work. The choice changes which dimension of the drawer matters, which rails it takes and which cabinets it suits. Here is how we decide in our Las Vegas shop.
Quick answer. In a front to back file drawer the rails run from front to back and the drawer is sized by its width: at least 14 1/4 in for letter with 5/8 in sides. In a lateral file drawer the rails run side to side on aluminum L bar and the drawer is sized by its depth: at least 14 5/16 in deep for letter and 17 5/16 in for legal. Choose front to back for narrow, deep drawers and lateral for wide drawers or for legal files in a cabinet too narrow for legal front to back.
What is a front to back file drawer?
A front to back file drawer has two rails running from the front of the box to the back, and the folders hang across them facing you. You open the drawer and flip through the folders toward you. The drawer width sets letter or legal: 12 1/4 in or 15 1/4 in rail spread, so a box at least 14 1/4 in or 17 1/4 in wide with 5/8 in sides. Depth only decides how many folders fit.
What is a lateral file drawer?
A lateral file drawer has its rails running side to side, one along the front wall and one along the back, and the folders hang between them facing left and right. You flip through the folders sideways. Now the drawer depth sets letter or legal, and the width only decides how many folders fit. A lateral letter drawer needs a box at least 14 5/16 in deep with 5/8 in sides.
Lateral and front to back compared
The two layouts hold the same folders. What changes is the dimension that has to meet a minimum, the rail stock, and how you reach the files. This table uses our standard 5/8 in sides.
| Front to back | Lateral | |
|---|---|---|
| RAILS RUN | Front to back, along the sides | Side to side, along the front and back |
| SIZED BY | Box width | Box depth |
| LETTER MINIMUM | 14 1/4 in wide | 14 5/16 in deep |
| LEGAL MINIMUM | 17 1/4 in wide | 17 5/16 in deep |
| DOUBLE MINIMUM | 27 1/4 in wide (double letter) | 27 5/16 in deep (double lateral letter) |
| RAIL STOCK | 1/8 x 1 in flat bar up to a 22 in span, L bar beyond | 1/2 x 1 in aluminum L bar, always |
| FOLDERS FACE | Toward you | Left and right |
| BEST IN | Narrow, deep drawers | Wide drawers, or deep drawers too narrow for legal |
| RAIL ALIGNMENT | Left, center or right | Not needed, rails run the full width |
Minimum depth for a lateral file drawer
A lateral letter file drawer needs a box at least 14 5/16 in deep with 5/8 in sides, and a lateral legal file drawer needs 17 5/16 in. Those are 1/16 in more than the matching front to back widths, because the lateral rails sit against the front and back walls. Thinner sides lower the minimum by 1/4 in, thicker sides raise it by 1/4 in.
| Lateral layout | 1/2 in sides | 5/8 in sides (our standard) | 3/4 in sides | Undermount runner length, 5/8 in sides |
|---|---|---|---|---|
| LATERAL LETTER | 14 1/16 in | 14 5/16 in | 14 9/16 in | 15 in or longer |
| LATERAL LEGAL | 17 1/16 in | 17 5/16 in | 17 9/16 in | 18 in or longer |
| DOUBLE LATERAL LETTER | 27 1/16 in | 27 5/16 in | 27 9/16 in | 30 in |
| DOUBLE LATERAL LEGAL | 33 1/16 in | 33 5/16 in | 33 9/16 in | not available, past our 30 in limit |
On undermount boxes the depth is the runner length, so pick a runner at least as long as the minimum. A double lateral letter drawer needs a 30 in runner, which on our configurator means Blum MOVENTO 763, Grass Dynapro, Salice Progressa+, Würth PRO600 Heavy Duty, or our standard notch. Without notching, our custom box runs 9 to 24 31/32 in deep, which covers lateral letter and legal on side mount slides but not double lateral. Check that your cabinet is deep enough for the runner in our undermount slide guide.
Which desks and cabinets suit each layout?
Front to back suits the narrow, deep drawer, like a desk pedestal or a single base cabinet. Lateral suits the wide drawer, like a credenza or a wide base cabinet, and it rescues legal files in a cabinet that is deep but narrow. A good test: if the drawer is wider than it is deep, look at lateral first.
Desk pedestal drawers
Front to back. A pedestal drawer is usually narrow and deep, which is exactly what a letter layout wants: a 14 1/4 in box and as much depth as the desk allows.
Kitchen base cabinets
Front to back in a single base cabinet 18 in or wider. Standard base cabinets are about 24 in deep, so the depth is never the limit; the opening width is.
Credenzas and wide built ins
Lateral. A wide, shallower drawer gives one long run of folders you flip side to side, with no pair of rails down the middle.
Narrow but deep cabinets
Lateral legal. A cabinet too narrow for a 17 1/4 in legal box can still take legal files sideways if the box is at least 17 5/16 in deep.
Shallow, wide drawers
Front to back. If the box is under 14 5/16 in deep, lateral letter will not fit, but two letter bays front to back will in a box 27 1/4 in or wider.
For the full width chart, including double layouts and the triple layouts we handle by instant quote, see letter vs legal file drawer dimensions. Height is the same for both layouts, 10 1/4 in as standard or 10 3/8 in with a 1/2 in bottom, explained in how tall a file drawer needs to be.
Flat bar or L bar rails?
Front to back drawers use 1/8 x 1 in flat bar rails for spans up to 22 in. Past 22 in, and on every lateral drawer, the rails step up to 1/2 x 1 in aluminum L bar, which stays straight over a long run of folders. Lateral rails span the full inside width of the box, so on a 30 in drawer they carry folders across nearly 29 in.
Every file drawer we build comes with its rails unless you choose slots only, no rails. They are anodized aluminum, cut to fit and set in slots cut into the top edge of the box: in the front and back for a front to back layout, and in the sides for a lateral layout.
Can one file drawer do both?
Not in one box from our configurator. Each file drawer is cut for one direction, front to back or lateral, and the two rail sets would cross, so only one could ever be installed at a time. If you want one box cut for both directions, describe it on the instant quote and we tell you whether we can build it. One box can hold both letter and legal, though: the letter or legal option cuts slots for both spacings and ships with both rail sets.
The practical way to combine them is across a set of drawers: a front to back drawer in the desk pedestal and a lateral drawer in the credenza behind it, both built to the same species and side thickness so they match. Our Baltic Birch and Hard Maple (Select Grade) boxes are built the same way whichever layout you pick.
Finish the install
Slides for wide and lateral file drawers
A wide lateral drawer full of paper is one of the heaviest drawers in a house, so check the slide rating before you pick. We make no load claim for the box itself. The slide makers rate their runners by model: Blum TANDEM 563 at 100 lb, Blum MOVENTO 763 at 125 to 170 lb, Würth PRO600 Heavy Duty at 130 to 150 lb and Salice Progressa+ at 170 lb static. Würth PRO100 side mount slides are rated 100 lb.
Undermount slides
Blum and Würth runners. We notch and drill the file drawer to match the model you pick.
Shop undermount →Side mount slides
Würth side mount slides, standard or soft close, for face frame cabinets.
Shop side mount →Clips and brackets
Front locking devices and brackets. We can press the clips on for you when you order the box.
Shop clips and brackets →How to choose between lateral and front to back
1. Measure width and depth
Work out the outside box width and depth from your opening and slides. Our measuring guide walks through it.
2. Check front to back
Is the box at least 14 1/4 in wide for letter or 17 1/4 in for legal, with 5/8 in sides? Then front to back works.
3. Check lateral
Is the box at least 14 5/16 in deep for letter or 17 5/16 in for legal? Then lateral works too.
4. Pick by how you work
If both fit, choose front to back to flip toward you, or lateral for one long run in a wide drawer. Then build it on the custom file drawer box page, where the live preview flags any layout your box is too small for and every option’s price shows as you build it.
Lateral and front to back file drawer questions
What is the difference between a lateral and a standard file drawer?
A standard file drawer runs its rails front to back and is sized by width, at least 14 1/4 in for letter with 5/8 in sides. A lateral file drawer runs its rails side to side and is sized by depth, at least 14 5/16 in for letter. Both use the same hanging folders.
How deep does a lateral file drawer need to be?
With 5/8 in sides, a lateral letter drawer needs a box at least 14 5/16 in deep and a lateral legal drawer needs 17 5/16 in. With 1/2 in sides take off 1/4 in; with 3/4 in sides add 1/4 in.
Can I fit legal files in a narrow cabinet?
Often, yes, by turning them lateral. Legal front to back needs a box 17 1/4 in wide, but lateral legal only needs the box to be 17 5/16 in deep, so a narrow, deep cabinet can still hold legal folders sideways.
What rails does a lateral file drawer use?
Lateral file drawers use 1/2 x 1 in aluminum L bar rails along the front and back walls, because the rails span the full width of the drawer. Front to back drawers use 1/8 x 1 in flat bar up to a 22 in span.
Can you build a double lateral file drawer?
Double lateral letter, yes, on a 30 in undermount runner, because the box must be at least 27 5/16 in deep with 5/8 in sides. Double lateral legal needs 33 5/16 in, which is past our 30 in depth limit.
Can one drawer take both lateral and front to back rails?
Not from our configurator; each file drawer is cut for one direction. The front to back and lateral rails would cross, so only one set could be installed at a time anyway. For a box cut both ways, ask on the instant quote.
Front to back or lateral, built to your box size
Enter your box width and depth, your slides and the layout you want, and we build the file drawer to the 1/32 inch, rails included. Every option shows its price as you build it. For a layout the configurator does not show, describe it on the instant quote.