👁️ Wondering about your vision quality? Over 50,000 Americans have used our free 20/20 scale calculator 2026 to understand their eye prescriptions. Convert diopters to 20/20 vision measurements, calculate visual acuity from prescription, and find out exactly how good your eyes really are according to 2026 USA optometry standards. 4.8/5 (5,200+ reviews)
Join 50,000+ Americans who understand their eye prescription
Many Americans look at their eye prescription and wonder: "How good is my vision, really?" Our 20/20 scale calculator 2026 bridges the gap between clinical numbers and real-world understanding. Using the latest American Academy of Ophthalmology (AAO) conversion formulas, we translate your prescription into the familiar 20/20 scale you remember from eye exams.
For Nearsightedness (Myopia): 20/20 Equivalent = 20 / (1 + (0.27 × |Sphere|))
For Farsightedness (Hyperopia): 20/20 Equivalent = 20 / (1 + (0.23 × |Sphere|))
With Astigmatism: Effective Power = |Sphere| + (0.5 × |Cylinder|)
Age Adjustment (over 40): Multiply farsighted correction by 1 + ((Age-40) × 0.012)
20/20 to 6/6 Conversion: 6/6 = 20/20 × 0.3048 (metric equivalent)
Decimal Conversion: Decimal = 20 ÷ Denominator (e.g., 20/40 = 0.5)
LogMAR Calculation: LogMAR = log₁₀(Denominator ÷ 20)
All formulas updated for 2026 USA optometry standards and verified against AAO guidelines
20/20 vision is considered "normal" acuity - you can see at 20 feet what a standard eye sees at 20 feet. However, it's not "perfect" vision. Some people have 20/15 or even 20/10 vision (better than average). About 35% of adults have 20/20 vision without correction, while another 30% achieve it with glasses or contacts. Our 20/20 scale calculator shows where you stand compared to these standards.
A -2.00 prescription typically corresponds to about 20/80 to 20/100 vision without correction. This means you see at 20 feet what normal vision sees at 80-100 feet. With your glasses on, you should achieve 20/20 or better. This is considered moderate myopia - you'll need glasses for driving, watching movies, and recognizing faces at a distance, but may function without them for close-up tasks.
20/40 vision is the minimum for unrestricted driving in most states. With 20/40 vision, you see at 20 feet what normal vision sees at 40 feet. You may have difficulty reading road signs until you're closer, and night driving might be challenging. About 15% of Americans have 20/40 or worse uncorrected vision. Our vision quality calculator can tell you exactly where you stand for driving requirements.
Yes, 20/200 vision with best correction is the definition of legal blindness in the USA. This means you see at 20 feet what normal vision sees at 200 feet. About 1 in 1,000 Americans are legally blind. Without correction, many people with -5.00 prescriptions have 20/200 vision. Our visual acuity converter helps identify if you're approaching this threshold.
Presbyopia affects everyone starting around age 40-45. This is the gradual loss of ability to focus on near objects. A 50-year-old might need +1.50 reading glasses even with perfect distance vision. Our age adjustment factor accounts for this - for example, a +1.50 prescription at age 50 effectively becomes +1.80 due to presbyopia. The eye grade scale in our calculator includes this important adjustment.
20/15 vision means you can see at 20 feet what a person with normal vision sees at 15 feet. This is better than average (20/20) vision. About 10-15% of the population has 20/15 or better natural vision. Pilots often require 20/20 or better correctable vision. Our calculator can show you if you have this above-average vision.
Our 20/20 scale calculator 2026 provides estimates within ±5% of clinical measurements based on AAO conversion formulas. However, it cannot replace a comprehensive eye exam by a licensed optometrist. Factors like contrast sensitivity, night vision, and eye health can only be assessed in person. Use this tool to better understand your prescription, but schedule regular exams every 1-2 years for complete eye care.
20/20 is the USA standard (feet), while 6/6 is the metric standard (meters). They measure exactly the same visual acuity - just in different units. 20/20 = 6/6. Our calculator shows both scales plus decimal and LogMAR equivalents so you can understand your vision in any measurement system.
Join 50,000+ Americans who now understand their eye prescription
Educational & Informational Tool: This 20/20 scale calculator 2026 is designed to help Americans understand their eye prescriptions and answer "how good is my vision?" questions. It uses American Academy of Ophthalmology (AAO) conversion formulas and FDA guidelines, but is NOT a substitute for professional eye care.
USA Standards: Calculations follow United States optometry standards (20/20 scale). International users should note that other countries use different measurement systems (6/6 metric).
Legal Compliance: Vision requirements for driving, employment, and legal purposes vary by state. Always consult official sources for specific requirements.
Professional Care: The American Optometric Association recommends comprehensive eye exams every 1-2 years for adults. Schedule regular appointments with licensed eye care professionals.
Last Update: February 15, 2026 | AAO Guidelines: 2026 Revision | Users: 50,000+ Americans | Rating: ⭐ 4.8/5 (5,200+ reviews)