Size codes, explained

Before a single fruit is packed, its diameter decides which market it can go to. Here is how the international size scale for citrus actually works.

Every carton of export citrus carries a size code. Behind that code sits a simple rule written into the UNECE standard FFV-14, the Codex standard for oranges and the EU marketing standard: fruit are graded by their equatorial diameter, and each code covers a fixed band of millimetres.

Minimum sizes

The scale starts with a floor. Under UNECE FFV-14, oranges must measure at least 53 mm. Lemons and satsumas and other mandarins start at 45 mm, and clementines at 35 mm. The Codex standard for oranges uses the same 53 mm limit and excludes anything smaller.^1,2

Diameter has a precise meaning. The US grade standard defines it as the greatest dimension measured at right angles to the line from stem to blossom end, which is exactly how a caliper should be held.³

Codes overlap on purpose

For oranges, code 0 covers 92 to 110 mm and code 13 covers 53 to 60 mm, with the codes in between overlapping one another. Mandarins use their own scale, from 1‑XXX at 78 mm and above down to code 4 at 50 to 60 mm. Lemons run from code 0 at 79 to 90 mm to code 7 at 45 to 52 mm.¹ The overlap gives packhouses room to fill a count without forcing a hard cut at every boundary.

Uniformity inside the box

A packed box must also be uniform. When the smallest fruit in a package is below 60 mm, the spread between smallest and largest may not exceed 10 mm. Between 60 and 80 mm the limit is 15 mm, and between 80 and 110 mm it is 20 mm. The current EU regulation keeps the same rule.^1,4

Tolerances

All classes allow 10 percent of fruit to fall in the size immediately above or below the declared one. That tolerance stops at a hard minimum: 50 mm for oranges, 43 mm for mandarins and lemons, and 34 mm for clementines.¹