Hoat-kok bīn-chek 550,000 km², sī se Au-chiu siōng toā ê kok-ka. I piⁿ--á ū Pak-hái, Eng-kok hái-kiap (Hoat-gí: La Manche, chhiú-ńg), Tāi-se-iûⁿ, kap Tē-tiong-hái; hái-hoāⁿ lóng-chóng sī 3,427 kong-lí tn̂g.
Tî-liáu tang-pak-pêng ê pō͘-hūn, Hoat-kok ê piⁿ-kài chú-iàu sī thian-jiân ê kài-soàⁿ. Lâm-pêng ê Pyrénées soaⁿ-me̍h kā Hoat-kok kap Se-pan-gâ hun-khui. Tang-pêng ê Alpes kap Jura soaⁿ-me̍h sī i kap Í-tāi-lī í-ki̍p Sūi-se ê chū-jiân piⁿ-kài.
Hoat-kok siōng tn̂g ê hô sī Loire-hô, tùi tang-lâm-pō͘ ê Ardèche-khu lâu khì sai-pêng ê Tāi-se-iûⁿ. Loire-hô ū 1,020 kong-lí tn̂g; i 117,000 km² ê liû-he̍k chhiau-kòe Hoat-kok bīn-chek ê gō͘-hun-chi-it.