| 20 ft | 6 m | Decimal | 4 m | Log MAR |
|---|---|---|---|---|
| 20/630 | 6/190 | 0.032 | 4/125 | +1.5 |
| 20/500 | 6/150 | 0.04 | 4/100 | +1.4 |
| 20/400 | 6/120 | 0.05 | 4/80 | +1.3 |
| 20/320 | 6/95 | 0.06 | 4/63 | +1.2 |
| 20/250 | 6/75 | 0.08 | 4/50 | +1.1 |
| 20/200 | 6/60 | 0.1 | 4/40 | +1.0 |
| 20/160 | 6/48 | 0.125 | 4/32 | +0.9 |
| 20/125 | 6/38 | 0.16 | 4/25 | +0.8 |
| 20/100 | 6/30 | 0.2 | 4/20 | +0.7 |
| 20/80 | 6/24 | 0.25 | 4/16 | +0.6 |
| 20/63 | 6/19 | 0.32 | 4/12.5 | +0.5 |
| 20/50 | 6/15 | 0.4 | 4/10 | +0.4 |
| 20/40 | 6/12 | 0.5 | 4/8 | +0.3 |
| 20/32 | 6/9.5 | 0.63 | 4/6.3 | +0.2 |
| 20/25 | 6/7.5 | 0.8 | 4/5 | +0.1 |
| 20/20 | 6/6 | 1.0 | 4/4 | 0 |
| 20/16 | 6/4.8 | 1.25 | 4/3.2 | -0.1 |
| 20/12.5 | 6/3.8 | 1.6 | 4/2.5 | -0.2 |
| 20/10 | 6/3 | 2.0 | 4/2 | -0.3 |