What Size Walk-In Cooler Do I Need?

By Renato J. Alonso, Founder and President, Qube Cold Storage Solutions · Updated October 28, 2026

Size a walk-in two ways and use the smaller answer: the largest box your space can hold, and the box your product actually needs. For the second, add up what you keep on hand just before a delivery, then divide by 0.40 to 0.45, because only 40% to 45% of a walk-in's volume can actually hold product. The rest is aisle, air space and clearance. For example, 250 cubic feet of product on hand needs about 556 cubic feet of walk-in, which is a 12' x 8' cooler.

Step 1: find the largest walk-in your space can hold

• Measure wall to wall at the floor, around columns, pipes, floor drains and anything mounted low on the walls.
• Leave a small gap to each existing wall. About 2 inches is typical; the joint is closed with trim after the walk-in is assembled.
• Round down to whole feet. A 12' x 9' room holds an 11' x 8' walk-in, not a 12' x 9'.
• Keep about 3 feet clear outside the door so it can swing open, more if carts or hand trucks go in.

Step 2: check it against what you store

1. Count what is on hand at the peak, just before your largest delivery arrives: cases, kegs, bins and bulk product.
2. Convert to cubic feet. Measure a few of your typical cases (length x width x height in inches, divided by 1,728) and multiply by the count.
3. Divide by 0.45 (or 0.40 to be safe) to get the walk-in volume you need.
4. Divide by the inside height to get the floor area, then pick the size from the chart below.

Adjust for how often you get deliveries. Twice a week needs more room than daily. A business heavy in fresh produce or whole proteins needs more room than one built on prepared product.

Worked example: 250 cubic feet on hand

Product on hand at peak	250 cu ft
Walk-in volume needed	250 ÷ 0.45 = about 556 cu ft
Smallest size that holds it	12' x 8' cooler: 603 cu ft inside

If your space can hold more than that, the next size up costs less now than a second walk-in later. If your space cannot hold it, the answer is often a taller box, a second room, or a combination cooler and freezer laid out to fit.

Walk-in sizes, inside dimensions and usable space

Walk-ins are named by their outside size. With 4-inch walls, the inside is 8 inches smaller in each direction. This chart uses Qube's standard 7'7" outside height, which gives 7'3" inside a floorless cooler.

Nominal size (outside)	Inside dimensions	Inside floor area	Inside volume	Usable for food (40% to 45%)
6' x 6'	5'4" x 5'4"	28 sq ft	206 cu ft	82 to 93 cu ft
6' x 8'	5'4" x 7'4"	39 sq ft	284 cu ft	113 to 128 cu ft
8' x 8'	7'4" x 7'4"	54 sq ft	390 cu ft	156 to 176 cu ft
8' x 10'	7'4" x 9'4"	68 sq ft	496 cu ft	198 to 223 cu ft
8' x 12'	7'4" x 11'4"	83 sq ft	603 cu ft	241 to 271 cu ft
10' x 10'	9'4" x 9'4"	87 sq ft	632 cu ft	253 to 284 cu ft
10' x 12'	9'4" x 11'4"	106 sq ft	767 cu ft	307 to 345 cu ft
10' x 14'	9'4" x 13'4"	124 sq ft	902 cu ft	361 to 406 cu ft
12' x 16'	11'4" x 15'4"	174 sq ft	1,260 cu ft	504 to 567 cu ft
12' x 20'	11'4" x 19'4"	219 sq ft	1,589 cu ft	635 to 715 cu ft

Floorless cooler, 4-inch walls and ceiling, 7'7" outside height. A walk-in with an insulated floor loses about 4 more inches of inside height; a freezer almost always has one.

Step 3: check the rest of the space before you settle on a size

• Measure the ceiling. A top-mount refrigeration unit sits on the walk-in's roof and needs clear space above it for service and airflow.
• Measure the way in. Panels arrive flat on pallets. Every door, hallway and turn between the truck and the room has to fit them.
• Plan the door. A standard walk-in door is 36" x 78". Carts, kegs and pallets may need a wider door.
• Plan the refrigeration. Where will the condensing unit go: on top, on the roof, or outside? See self-contained vs remote.

Common mistakes

• Sizing from outside dimensions. An 8x8 is 7'4" x 7'4" inside, and shelving takes another 18 to 24 inches off each side it runs along.
• Forgetting the aisle. You need room to stand, turn with a case and close the door behind you. That is most of the 55% to 60% you cannot fill.
• Buying for today. Walk-ins last for years. If volume is growing, the next size up is cheaper now than a second walk-in later.
• Ignoring the freezer. Many businesses size the cooler carefully and guess at the freezer. Size both from the same delivery schedule.

Questions people ask

How do I figure out what size walk-in cooler I need?

Find the largest size your space holds, leaving about 2 inches to each wall. Then add up the product you keep on hand at the peak, in cubic feet, and divide by 0.45, because only 40% to 45% of a walk-in holds product. Pick the size that meets both.

What are the inside dimensions of an 8x8 walk-in cooler?

With 4-inch walls, an 8' x 8' walk-in is 7'4" x 7'4" inside. Inside height is about 7'3" for a floorless cooler with a 7'7" outside height.

How much of a walk-in cooler is usable?

About 40% to 45% of the inside volume. The rest is the aisle, air space around the product, and clearance from the walls, ceiling and evaporator.

What is the smallest walk-in cooler?

6' x 6' is a common small size. It gives about 28 square feet inside, 5'4" x 5'4".

Are walk-in sizes inside or outside dimensions?

Outside. A walk-in is named by its nominal exterior size, so the inside is smaller by twice the wall thickness in each direction.

How much space do I need around a walk-in?

About 2 inches to each existing wall, closed with trim, and about 3 feet clear outside the door so it can swing open. A top-mount refrigeration unit also needs clear space above the walk-in.

Sources

• Inside dimensions and volumes calculated by Qube from its standard construction: 4-inch walls and ceiling, 7'7" outside height, floorless.