Free tool
Sign Visibility Calculator
What size font and how big a sign do you need? Pick the viewing scenario or punch in your own distance and speed. Based on outdoor advertising research from the OAAA.
Or set your own:
Recommended specs
12x18 (small yard sign)
Sign size for clear visibility from 60 feet at 25 mph
Minimum letter height (readable)
At 1" per 30 ft of distance — meets visibility threshold
2.0"
Comfortable letter height
At 1" per 40 ft — easier to read at speed, less eye strain
1.5"
Viewing window
Time the sign is in the viewer's field of view at 25 mph
1.6s
Max words for readability
At ~1.5 words per second, more than this won't be read in time
2 words
The visibility math
The outdoor advertising industry standard is 1 inch of letter height per 30 feet of viewing distance for basic readability. For comfortable reading (especially by drivers at speed), use 1 inch per 40 feet.
Why distance matters more than size. The human eye's letter recognition threshold scales linearly with distance. A 2-inch letter is recognizable from 60 feet but unreadable from 200 feet — no matter how bold the design.
Why speed matters. A driver passing your sign at 35 mph has roughly 1.7 seconds of "in view" time at a 60-foot viewing distance. At ~1.5 words per second of reading speed, that's a 2-3 word maximum. Cram 6 words into the same sign and the driver reads none of them.
Sign Visibility FAQ
What font size should outdoor signs use?
Industry standard: 1 inch of letter height for every 30 feet of intended viewing distance (readability threshold). For comfortable reading, use 1 inch per 40 feet. So a sign viewed from 60 feet needs 2-inch letters at minimum, 3-inch for comfort. A highway sign viewed from 400 feet needs 13-inch letters minimum.
How many words should a yard sign have?
For drivers at 25-35 mph, 3-5 words maximum. For pedestrians or slow traffic (under 10 mph), 5-8 words. The viewing window at speed determines how much text the brain can process before the sign is out of view. Real-estate yard signs are 2-3 words (OPEN HOUSE, FOR SALE, FOR LEASE) plus a phone number for a reason.
How big should a yard sign be?
Most-ordered: 18x24 (visible 30-40 ft, good for residential streets). For busier roads: 24x36 (visible 60-80 ft). For commercial frontage and construction sites: 4x8 panel (visible 100+ ft). Match the size to where the sign sits, not where the headquarters is.
Can I use thin or fancy fonts on outdoor signs?
No. Sun bleach, weather wear, and viewing distance all reduce font contrast over time. Use bold sans-serif fonts (Helvetica Bold, Arial Black, Impact, Bebas Neue) at 700+ weight. Thin fonts and decorative scripts get unreadable past 15-20 feet even when new.
What sign size do I need for a freeway billboard?
Freeway signs (60-75 mph traffic) require commercial billboard size — typically 14x48 feet (mini-billboard) or 20x60 feet (full billboard). Our largest banner is 8x20 feet, which works for parking lot frontage but not freeway-rated billboards. For true highway signage, a specialty billboard printer is required.