The aspect ratio of an image is its width divided by its height.
The following table illustrates the common aspect ratios presented on DVD along with the total active pixels presented in each possible DVD format. I have highlighted the best formats in green.
| Aspect Ratio |
4x3 PAL |
16x9 enhanced PAL |
4x3 NTSC |
16x9 enhanced NTSC |
| 1.33:1 |
720 x 576 = 414,720 |
538 x 576 = 309,888 |
720 x 480 = 345,600 |
538 x 480 = 258,240 |
| 1.66:1 |
720 x 461 = 331,920 |
671 x 576 = 386,496 |
720 x 384 = 276,480 |
671 x 480 = 322,080 |
| 1.78:1 |
720 x 430 = 309,600 |
720 x 576 = 414,720 |
720 x 358 = 257,760 |
720 x 480 = 345,600 |
| 1.85:1 |
720 x 414 = 298,080 |
720 x 554 = 398,880 |
720 x 345 = 248,400 |
720 x 461 = 331,920 |
| 2.35:1 |
720 x 326 = 234,720 |
720 x 436 = 313,920 |
720 x 271 = 195,120 |
720 x 363 = 261,360 |
References: