Tools · Professional education
Conversion of Visual Acuity
Choose a value in any field to update all four equivalent notations.
About these conversions
Decimal = 20 ÷ Snellen feet denominator. The 6-metre denominator = 0.3 × the 20-foot denominator. logMAR = −log₁₀(decimal). Displayed decimal and logMAR values are rounded to three decimal places; calculations use the unrounded values.
This is a notation converter, not a vision test. Rounded chart labels may differ slightly. Counting fingers, hand movements and light perception are not assigned numerical equivalents here.
Both languages use the same values, ranges and calculations. Values are not saved or sent to a server.
Holladay JT. Proper method for calculating average visual acuity. J Refract Surg. 1997;13:388–391.