Guide · 5 min read
How big should sign lettering be to read from a distance?
As a rule of thumb, allow roughly 25 mm of letter height for every 3 m of viewing distance for basic legibility, and more for impact or for drivers passing at speed. Strong contrast, a clear font, generous spacing and fewer words matter as much as size.
How tall should sign letters be?
A useful rule of thumb is roughly 25 mm of letter height for every 3 m of viewing distance for basic legibility. On that basis, a sign read from 30 m away needs letters of at least 250 mm, and one read from 60 m needs around 500 mm.
That is the minimum for someone to read it if they look. For a name that catches the eye and reads at a glance, go bigger. Letter height here means the height of a capital letter; lower-case letters are shorter, so allow for that if your name is in lower case.
How do you work out your viewing distance?
Stand where your customers will first see the sign and measure, or pace out, the distance to the frontage. For a pedestrian high street, that might be the far pavement or the next shop along. For a roadside site, it is the point where drivers need to spot you in time to slow down and turn.
Think about speed. A driver at 30 mph covers more than 13 m every second, so a sign that only becomes readable at 20 m gives them barely a second and a half. Roadside and retail-park signs need much larger letters than the basic rule suggests.
Why does contrast matter as much as size?
Contrast between the letters and the background often decides whether a sign is readable at all. Dark letters on a light background, or light letters on a dark one, are the easiest to read. Mid-tones together, such as red on green or grey on blue, blur at a distance even when the colours look striking up close.
Check the sign at night too. A non-illuminated sign under a streetlight, or halo letters against a dark wall, may lose contrast after dark. Metallic and mirror finishes can be hard to read at certain angles because they reflect the sky or the street.
Which fonts read best on a sign?
Clear, open letterforms with even stroke widths read best at a distance. Simple sans-serif and sturdy serif typefaces both work well; thin scripts, condensed fonts and decorative styles with fine detail do not.
If your logo uses a delicate font, keep it for the brand mark and set the rest of the wording, such as what you do and your phone number, in a plainer font. Avoid all capitals for longer lines, because mixed case is easier to read quickly.
How much spacing do letters need?
Letters that are too close together merge into a block at a distance, especially when lit. Allow comfortable spacing between letters and words, and clear space around the whole name: a sign packed edge to edge reads worse than a smaller name with room to breathe.
As a starting point, keep the main lettering to around 60–70% of the fascia height, leaving a margin above and below. For lit letters, slightly wider spacing stops the glow from neighbouring letters running together.
Why should you use fewer words?
Every extra word makes the others smaller. People glancing at a fascia usually take in only a few words: who you are and what you do. A clear hierarchy works best:
- The business name, largest.
- One short line on what you do, smaller.
- Phone number or website only if there is room without shrinking the name.
- Opening hours, service lists and social handles on the door or window, not the fascia.
How do you test a design before it is made?
The most reliable test is a full-size print. Print the main word or two at the proposed letter height, tape it in position, then walk to your viewing distance and look. Try it from a car if passing traffic matters.
We send a scaled design proof placed on a photo of your frontage before anything is made. Nothing goes into production until you approve it, so there is time to adjust the size, spacing or colours.
Want a second opinion on your sign?
Send a photo and a rough size. We’ll tell you what would work, what it’s likely to cost and whether consent is needed.