noun
sum of three dimensions; total of length, width, and height
Used primarily in shipping and logistics contexts to describe the combined measurement of a package's three sides.
この荷物は三辺合計が160cmを超えているので、追加料金がかかります。
This package exceeds 160 cm in total dimensions, so an additional fee applies.
宅配便では、三辺合計が170cm以内の荷物を取り扱っています。
The courier service handles packages with a total dimension sum of up to 170 cm.
Compound of 三辺 (three sides) and 合計 (total sum). The reading さんぺん follows standard rendaku for 三 (さん) + 辺 (へん).