How Many Boxes Fit on a Pallet? Layer Patterns, Height Limits, Overhang

I get asked "how many boxes fit on a pallet?" constantly, and the honest answer is one nobody loves: you calculate it, you don't look it up. It's cartons per layer × number of layers, with a height limit, a weight limit, and the overhang rule all pulling against you. Let me walk you through how I actually work it out; the pallet calculator does the same math in a blink and draws you a top-view diagram while it's at it.

Step 1 — Get the cartons-per-layer count right

On a GMA pallet (1219 × 1016 mm) with a carton of L × W footprint, start with the obvious grid: floor(1219 ÷ L) × floor(1016 ÷ W) — then don't stop there. Spin the grid and test the rotated version, and try the mixed patterns that mix both orientations in a single layer. On a EUR pallet, swap in the 1200 × 800 mm deck from the EPAL spec. I've seen orientation alone move the count by a whole row:

Grab the wrong grid and you've just tossed 25% of every layer — free capacity you leak on every single pallet you ship, forever. Mixed patterns pay off when the carton is big relative to the pallet and leaves a fat strip of empty deck that a rotated row can grab back. The 600 × 400 mm carton on GMA is the textbook example I always reach for:

Step 2 — Figure out how many layers you can go

layers = floor((max height − pallet height) ÷ carton height). Your height ceiling shows up from three directions, and you take whichever one bites first:

• Warehouse racking at the far end: usually 60–64 in total including the pallet in US distribution centers — but call and confirm, don't assume.

• Container clearance: a 40HC gives you 270 cm inside, so two stacked pallet loads each have to stay under ~132 cm including the pallet.

• Product strength: the bottom cartons carry the whole column. Weigh the carton's stacking strength (BCT/ECT) against the load sitting on it, and derate it for humidity and transit time — a carton that passes in the lab will crush after three humid weeks at sea. That gap between lab strength and voyage strength is exactly why ISTA transit-testing protocols exist.

Step 3 — Sanity-check the weight

max layers by weight = floor(pallet load rating ÷ (cartons per layer × carton weight)). And use the dynamic or racked rating, not the static one (more on that in pallet standards).

Working one all the way through: 300 × 250 × 200 mm cartons

Say the carton is 300 × 250 × 200 mm at 12 kg. GMA pallet, 145 mm tall, 1,500 mm max stack, 1,150 kg dynamic rating. Here's how it falls out:

• Per layer (Grid A): 16
• Layers by height: floor((1500 − 145) ÷ 200) = 6
• Layers by weight: floor(1150 ÷ (16 × 12)) = 5

• Result: 5 × 16 = 80 cartons, 960 kg, 1,145 mm tall — weight-bound, and you're leaving 355 mm of height headroom on the table.

Open this exact example in the pallet calculator and you'll see the layer diagram plus the pallet count for a whole order. When a pallet comes out weight-bound like this, take the hint: a beefier pallet or lighter cartons turns that wasted headroom into paying cargo.

When Amazon caps your height for you

Freight headed to FBA brings a hard outside constraint into the picture: US fulfillment centers want GMA pallets, and total height is often capped somewhere around 72 in (~180 cm) including the pallet — check the live routing guide, because programs and countries move the goalposts. Take that 300 × 250 × 200 mm carton at 10 kg, 500 units: run it with a 180 cm cap and you land on 16 per layer × 6 layers = 96 cartons per pallet at roughly 135 cm — the 1,000 kg weight limit bites before the height cap ever gets a say. That's 6 pallets for the order, the last one only half built. A few things I've learned the hard way: a stubby final pallet still eats a full pallet position on the truck, and an over-height pallet gets bounced or re-worked at the FC dock on your dime. Build to the cap minus a little breathing room (wrap adds 1–2 cm; keep labels visible) and you sidestep the re-work.

Column stack or interlock?

• Column stacking (corner-over-corner) keeps up to 100% of the carton's compression strength, because the corners are where a box is strongest. Reach for it when the cartons are the fragile part.

• Interlocked/brick patterns give up ~40–50% of that compression strength but knit the load together against shear and lean. Better for heavy, tough cartons riding rough transit legs.

• The compromise I lean on most: column-stack everything, interlock just the top layer, and let stretch wrap and corner boards handle the stability.

Overhang: honestly, just don't

Let a carton poke past the pallet edge and it loses up to a third of its stacking strength, gets crushed by whatever pallet parks next to it, and becomes the very first thing a carrier photographs when they deny your damage claim. If your carton won't tile the pallet cleanly, change the pattern or change the carton — the pallet calculator lets you dial the overhang allowance to zero and see what genuinely fits. Underhang costs you a touch of density (see freight density), but at least it's structurally sound.

The cost sting is easy to miss: overhang also puffs up the measured footprint of the load, and LTL carriers bill on the dimensions they measure, not the pallet size you had in mind. A couple of centimeters of carton hanging over each edge can nudge the billed dimensions into the next bracket — so you pay more to ship a weaker load. Fun.

The slip-ups that quietly cost money

• Measuring the product instead of the carton. Ti-hi math runs on outer carton dimensions — corrugate thickness, flap bulge, any bagging, all of it. A 5 mm slip per carton snowballs across four cartons in a row.

• Forgetting the pallet and wrap in your declared dimensions. Carriers measure the whole unit load. That ~145 mm pallet plus wrap can drop you into a worse density band or a fatter volumetric charge — I break that down in chargeable weight explained.

• Tall, skinny stacks. A load that's much taller than its footprint is wide turns tip-prone on a forklift; once stack height passes roughly twice the shorter base dimension, add strapping or trim a layer.

• Mixed-SKU "rainbow" pallets. Jam different carton footprints into one layer and you wreck both the tiling and the column alignment — count on fewer cartons per pallet and more damage than the single-SKU math promised.

• Nailing the pallet but forgetting the container. The tallest legal pallet isn't always the winner: two shorter loads that double-stack inside a container often beat one tall load that strands a meter of headroom. Check how many pallets fit in a container before you commit the ti-hi.