Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal)
Convert eye-test scores between the US 20/x, metric 6/x and decimal/LogMAR systems.
Three notations for the same thing: 20/20 (US) = 6/6 (metric) = 1.0 (decimal) = 0.0 LogMAR — all meaning you see at the reference distance what a 'normal' eye sees. 20/40 means you must be at 20 ft to read what others read at 40 (worse vision). LogMAR is the research standard because it's linear. None of these are a glasses prescription — that's a separate dioptre measurement.
Formula
For general information only — not medical advice, a diagnosis or a treatment plan. Consult a qualified healthcare professional before making health, diet, medication or exercise decisions.
Convert eye-test scores between the US 20/x, metric 6/x and decimal/LogMAR systems. The Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal) is a free, private 20/20 vision tool — every result computes instantly in your browser with no sign-up and no data upload.
About Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal)
Three notations for the same thing: 20/20 (US) = 6/6 (metric) = 1.0 (decimal) = 0.0 LogMAR — all meaning you see at the reference distance what a 'normal' eye sees. It applies 20/x (ft) = 6/x (m) = decimal (x ÷ ref); LogMAR = −log₁₀(decimal). Use the Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal) to get an instant, clearly-explained result with the working shown step by step — free, private and with the source method cited.
How to use Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal)
- 1Enter your details in the Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal) input fields above.
- 2The result updates instantly with the working and reference bands shown.
- 3Adjust any value to explore how it changes the outcome — it's free and unlimited.
Why use Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal)?
- ✓Instant 20/20 vision result that recomputes as you type — no waiting, no page reloads
- ✓100% client-side: your health data never leaves your browser
- ✓Shows the actual formula and your numbers substituted in, so you can see exactly how the result is reached
- ✓Based on published, citable sources (Snellen H 1862; LogMAR (Bailey-Lovie) chart conventions)
- ✓Free forever with no sign-up, account or app install
Frequently asked questions
How does the Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal) work?+
Three notations for the same thing: 20/20 (US) = 6/6 (metric) = 1.0 (decimal) = 0.0 LogMAR — all meaning you see at the reference distance what a 'normal' eye sees. The calculation uses the formula: 20/x (ft) = 6/x (m) = decimal (x ÷ ref); LogMAR = −log₁₀(decimal). Everything runs instantly in your browser as you type — your inputs are never uploaded.
Is the Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal) accurate, and what is it based on?+
The method is traceable to authoritative sources: Snellen H 1862; LogMAR (Bailey-Lovie) chart conventions. Results are estimates — individual variation always applies, so treat the output as a well-grounded starting point.
Is the Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal) free and private?+
Yes. It's completely free with no sign-up, and all computation happens locally in your browser, so none of your health data ever leaves your device.
Can I use this for medical decisions?+
This tool is for general information only and is not medical advice. Always consult a qualified healthcare professional before making health decisions.
What can I use the Vision Acuity Converter (20/20 ↔ 6/6 ↔ decimal) for?+
It's commonly used for 20/20 vision, 6/6 vision, snellen converter. Convert eye-test scores between the US 20/x, metric 6/x and decimal/LogMAR systems.
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