A regular compact disc or CD is 12cm. Knowing this we can figure out the following densities:

- CD-ROM: 700MB = 58.33MB per cm
- DVD: 4.7GB = 392MB per cm
- DVD-DL: 8.5GB = 725MB per cm
- Blu-ray: 25GB = 2.083GB per cm
- Blu-ray DL: 50GB = 4.167 per cm

If we take the following densities however and apply it to Laserdisc size discs of 30cm we get the following storage capacities:

- CD-ROM: 1749.9GB
- DVD: 11.76GB
- DVD-DL: 21.75GB
- Blu-ray: 62.49GB
- Blu-ray DL: 125.01GB