16x20 film exact size

Does anyone have an exact measurement of 16x20 film? I’m ordering some from Astrum and I just want to make sure I get the right measurements. I’m fairly certain it’s 404 x 505 mm but I just want to confirm.

zebra's 16x20“ cassettes have dimensions as standard: ”True 16x20in plate (406.4x508mm)".

tbw777 said:

zebra's 16x20“ cassettes have dimensions as standard: ”True 16x20in plate (406.4x508mm)".

Click to expand...

Which is expected, since Zebra is building them for glass plates. Put a film sheath inside that, and you'll reduce the cut film dimensions by a couple millimeters each way. With 4x5 instead of 102x127 the film is actually 100x125 mm. I'd expect the same reduction in 16x20, giving 404x506 mm -- but I've never handled actual 16x20 film or film holders.

now I'm curious myself.
From google images (there are deviations, tables with errors):