A “size 3” door closer is not 3 inches long. The number refers to closing force, measured against door width and weight. Get that wrong and the door either slams shut or never latches.
Two standards exist side by side. EN 1154 (Europe) uses grades 1 through 7. ANSI/BHMA A156.4 (North America) uses grades 1 through 6. They overlap but aren’t identical. Don’t cross-reference between the two without converting.
Bigger door, heavier door, higher size. That’s the whole chart in one line.
For most interior commercial doors, the rule looks like this:
| Door width | Interior (low traffic) | Interior (high traffic) | Exterior |
| Up to 750 mm (30″) | Size 2 | Talla 3 | Talla 3 |
| 750–900 mm (30″–36″) | Talla 3 | Size 4 | Size 4 |
| 900–1100 mm (36″–44″) | Size 4 | Talla 5 | Talla 5 |
| Over 1100 mm (44″+) | Talla 5 | Talla 6 | Talla 6 |
Add door weight into the equation. A solid-core oak door at 1100 mm needs more force than a hollow-core door the same width. The size chart assumes a standard core. Heavy or fire-rated cores push you up one grade.
The base chart assumes normal conditions. Adjust upward when you hit any of these:
When in doubt, go one size up. Undersizing is the most common cause of closers being replaced within the first year.
Three errors show up over and over:
Reading a size chart is a three-step check: width, weight, then conditions. Get those right and the closer will close the door reliably for years.
Skip a step, and you’ll be replacing the unit — or the door — sooner than planned.
Not sure which size fits your project? Send us the door dimensions, core type, traffic level, and any code requirements. OUDE will match you to the right size and adjustment range.


