Size Guide

Size Matters: The Science of Seeing Clearly

At Viking Signs, we don’t just guess how big your signs should be; we use a bit of engineering wizardry to make sure they’re perfect. To stay compliant and safe, we follow the global standard for safety symbols, ISO 7010.

If you want to get technical (and we do), we use the ISO viewing distance formula to ensure your team isn’t left squinting at a hazard.

The Magic Formula: L = Z x h

According to BS EN 1838 and ISO 3864, the maximum distance from which a sign is legible is calculated using this simple relationship: L = Z x h

  • L: The maximum viewing distance.
  • h: The height of the sign.
  • Z: The distance factor (the "secret sauce" that changes based on how the sign is lit).

Choosing Your "Z" Factor

Not all signs are created equal. How well a sign is lit changes how far away you can see it:

Illumination Type

Distance Factor (Z)

Why it matters

Internally Lit

200

These "glow-getters" are visible from twice as far.

Externally Lit

100

Standard signs lit by room lights or the sun.

The "Viking-Approved" Size Guide

We've done the math for you. Here’s how those numbers translate to the real world for standard, externally lit signs (Z=100):

Distance Needed

Sign Height (h)

Best For...

Up to 10 meters

100 mm

Small corridors and office doors.

Up to 15 meters

150 mm

Standard workshops and storage areas.

Up to 20 meters

200 mm

Larger warehouse bays and open offices.

Up to 30 meters

300 mm

High ceilings or long approach paths.

Up to 45 meters

450 mm

Construction sites and large industrial yards.

Why Trust the Formula?

  • Engineering wizardry: We focus on the reliable, high-standard result you need to keep your site compliant.
  • Self-Assured Quality: These calculations ensure your signs aren't just "wall art"—they are functional safety tools manufactured right here in the UK.
  • Speedy Compliance: We know you need it now. Understanding the right size means you order correctly the first time, and we’ll get it to you fast.

Viking Pro-Tip: If your environment is particularly dusty, poorly lit, or high-speed (like a forklift zone), we always recommend "sizing up" by one size to be safe.