Answered by: Maulana Mohammed Kamran Abid
How vast or big is the Arsh of Allah?
بِسْمِ اللهِ الرَّحْمنِ الرَّحِيْم
In the name of Allah, the Most Gracious, the Most Merciful
The Throne of Allah is so big that it is difficult for us to perceive it. Allah (SWT) says in the Holy Quran, “His Kursi extends over the heavens and the earth.” (Surah Baqarah, verse 255). This is said regarding the size of the Kursi, which the Throne encompasses. One can then only imagine how vast the Throne is.
It has been narrated that Ibn Mas’ood said, “Between the first heaven and the one above it is (a distance of) five hundred years. Between each of the heavens is (a distance of) five hundred years. Between the seventh heaven and the Kursi is (a distance of) five hundred years. Between the Kursi and the water is (a distance of) five hundred years, and the Throne is above the water. Allaah is above the Throne, and nothing whatsoever of your deeds is hidden from Him.”
Only Allah knows best
Written by Maulana Mohammed Kamran Abid
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
 Ibn Khuzaymah in al-Tawheed, p. 105; by al-Bayhaqi in al-Asmaa’ wa’l-Sifaat, p. 401
This answer was collected from DarulIftaBirmingham.co.uk, which is run under the supervision of Mufti Mohammed Tosir Miah from the United Kingdom.