Letter Height Calculator
How big do your letters need to be? Enter the distance your readers will be at, or the speed they'll be driving, and get a recommended letter height.
Recommended letter height
| Viewing distance | Recommended (1″ / 10 ft) | Bare minimum (1″ / 30 ft) |
|---|
Using the result
Letter height is measured on a capital letter. On a standard 18″ × 24″ yard sign, the space left after margins limits you to roughly 4–6 inch letters for a short headline, which is why short headlines win.
If the calculator asks for bigger letters than your sign can fit, you have three options: cut words, go up a size (see the size guide), or move the sign closer to where people will be.
Ready to check a real design? Try the Sign Preview tool.
About this calculator
What's the 10-feet-per-inch rule?
It's a widely used sign-industry rule of thumb: for comfortable, strong readability, plan about 1 inch of capital-letter height for every 10 feet of viewing distance. Bold, simple fonts and high contrast help it hold up.
Why does speed matter?
Faster traffic covers more ground while someone reads, so the sign has to be readable from farther away. At 30 mph a car covers 44 feet every second.
Is the maximum distance reliable?
Treat it as an upper bound for ideal conditions: bold sans-serif type, strong contrast, daylight and a clear line of sight. Real-world conditions are rarely ideal, so design to the recommended size.
Got a sign project? Let's price it out.
Tell us the size, quantity and deadline. We'll come back with material options and one delivered price: printing, hardware and shipping included.