The Quran

۞ وَلَكُم نِصفُ ما تَرَكَ أَزواجُكُم إِن لَم يَكُن لَهُنَّ وَلَدٌ ۚ فَإِن كانَ لَهُنَّ وَلَدٌ فَلَكُمُ الرُّبُعُ مِمّا تَرَكنَ ۚ مِن بَعدِ وَصِيَّةٍ يوصينَ بِها أَو دَينٍ ۚ وَلَهُنَّ الرُّبُعُ مِمّا تَرَكتُم إِن لَم يَكُن لَكُم وَلَدٌ ۚ فَإِن كانَ لَكُم وَلَدٌ فَلَهُنَّ الثُّمُنُ مِمّا تَرَكتُم ۚ مِن بَعدِ وَصِيَّةٍ توصونَ بِها أَو دَينٍ ۗ وَإِن كانَ رَجُلٌ يورَثُ كَلالَةً أَوِ امرَأَةٌ وَلَهُ أَخٌ أَو أُختٌ فَلِكُلِّ واحِدٍ مِنهُمَا السُّدُسُ ۚ فَإِن كانوا أَكثَرَ مِن ذٰلِكَ فَهُم شُرَكاءُ فِي الثُّلُثِ ۚ مِن بَعدِ وَصِيَّةٍ يوصىٰ بِها أَو دَينٍ غَيرَ مُضارٍّ ۚ وَصِيَّةً مِنَ اللَّهِ ۗ وَاللَّهُ عَليمٌ حَليمٌ

(Saheeh International)

And for you is half of what your wives leave if they have no child. But if they have a child, for you is one fourth of what they leave, after any bequest they [may have] made or debt. And for them [i.e., the wives] is one fourth if you leave no child. But if you leave a child, then for them is an eighth of what you leave, after any bequest you [may have] made or debt. And if a man or woman leaves neither ascendants nor descendants but has a brother or a sister, then for each one of them is a sixth. But if they are more than two, they share a third,¹ after any bequest which was made or debt, as long as there is no detriment [caused].² [This is] an ordinance from Allāh, and Allāh is Knowing and Forbearing.

These shares are divided equally between males and females.
This is a condition for any bequest. If it has been violated by the deceased, his bequest is not to be honored, or it may be adjusted by the executor. See 2:182.