Use this partition table guide when you install Ubuntu alongside windows.
- 1 GB - primary (1024) free space
- 20 GB - logical (20000) swap
- Rule of thumb is to keep double the size of your RAM.
- 40 GB - logical (40960) /
- 500 GB - logical (512000) /home
- Remaining - logical (26220) as external partition (for windows)
Cheers!!