GN 1/1, Half Pan or Full Sheet: Cutting Pads to Fit Standard Pans

Most complaints about pads not fitting come down to measuring the outside of a pan instead of the inside. A GN 1/1 pan is 530 × 325 mm across the rim, but the usable floor inside the lip is nearer 505 × 300 mm, and the difference is exactly where a pad either lies flat or curls up at one end. Get the floor dimension right and the rest of the sizing follows a simple rule.

The numbers for the pans you actually own

Inside-floor measurements, with a 10 to 15 mm wicking margin already deducted, give you the working pad size:

• GN 1/1 (530 × 325 mm outside): pad 480 × 280 mm, or 500 × 300 mm if the pan has straight sides and no rolled rim.
• GN 1/2 (325 × 265 mm): pad 280 × 220 mm, used for half-loads of fish portions or offal.
• GN 2/1 (650 × 530 mm): pad 620 × 500 mm, sized for whole salmon and large primals.
• US full sheet (457 × 660 mm): pad 430 × 630 mm; the half sheet takes a 430 × 300 mm pad.
• 600 × 400 crate: pad 580 × 380 mm, the workhorse size in butchery and poultry rooms.

If the pad has to be trimmed, cut it 5 mm oversize and fold the excess up the pan wall rather than cutting flush. A cut edge pressed hard against steel loses its wicking path, and a flush-cut pad slides under the weight of product. Trimming also exposes the SAP core on some constructions, which is why a pad should be bought in the right size rather than cut down from a bigger sheet.

Matching capacity to the pan, not just the footprint

Pan size sets the footprint; the product sets the loading. A GN 1/1 pan holding 10 kg of chicken thighs will release 250 to 400 ml over an overnight thaw, which a 480 × 280 mm pad at 400 g/m² SAP loading handles comfortably in one shift. The same pan holding 10 kg of whole mackerel can release 600 to 800 ml, and that pad will be finished by hour five.

The fix is not a bigger pad, because the pan will not take one. It is either a higher-loading pad in the same footprint — 600 to 700 g/m² — or a change of interval to four hours. A 480 × 280 mm pad at 700 g/m² holds roughly 40 percent more than the 400 g/m² version, and costs less than changing every pan in the kitchen.

Pan depth matters too. In a 20 mm deep pan the pad sits close to the product and wicking is direct. In a 65 mm deep pan with the product on a rack, the pad may be 40 mm below the product, and drip that lands beside the pad rather than on it never gets absorbed. Either raise the pad on a spacer or accept that a deep pan needs a larger pad to catch a scattered drip pattern.

Stacking pans, and the size that always seems to be missing

Stacked pans in a chiller are usually spaced by their own rims, which leaves 15 to 25 mm of air between the base of one pan and the product in the pan below. That gap is not enough to stop cross-drip if the upper pan’s pad is saturated. When pans are stacked more than two high, put a lid or a sheet of film on the second pan up, and keep the pad in the pan that is doing the actual thawing.

The size people ask for most often and stock least often is the 500 × 300 mm, which fits a straight-sided GN 1/1 with no margin to spare. It is worth carrying alongside the 480 × 280 mm, because the two together cover almost every 1/1 pan in a modern kitchen regardless of rim profile.

Standard formats for all the sizes above, including the crate pads used in butchery, are set out on the thawing pad size chart at florpoly.com. Measure the inside floor of your deepest pan before ordering, and size from that number rather than from the label on the pan.