What is the decimal equivalent of 6/6 (20/20) vision?

6/6 (20/20) = 1.0 decimal = 0.0 logMAR. 6/60 (20/200) = 0.1 decimal = 1.0 logMAR = severe visual impairment threshold. 6/12 (20/40) = 0.5 decimal = 0.3 logMAR = UK driving standard minimum.

Why is logMAR preferred over Snellen in research?

LogMAR provides a linear scale where each line change is an equal perceptual increment, enabling parametric statistical analysis. Snellen fractions cannot be averaged or analyzed statistically without conversion.

Snellen Visual Acuity to Decimal Conversion

Convert Snellen visual acuity (e.g., 6/6, 20/20, 20/200) to decimal notation and logMAR values for standardized documentation, research reporting, and cross-referencing visual impairment classification systems.

Use the full interactive calculator below, or

Snellen Visual Acuity to Decimal Conversion

Frequently Asked Questions

What is the decimal equivalent of 6/6 (20/20) vision?

Why is logMAR preferred over Snellen in research?