When 1-2-3-4-5-6-7-8-9-10-11-12 doesn't make sense.

[BoomerD]

Most gauges I see measure by 1/8th inch but the only reason no finer divisions than that, is because they'd be too close together (or too thin) to read from a distance. That's not entirely true, I mean you can taper down the base of a gauge so spread out the measurement marks but most aren't that elaborate.

I got a rain gauge on Amazon that makes even less sense, measures 1/10ths of an inch, but I liked the design that can be read 20' away.

Amazon.com

I like it...but it needs something to keep the birds off of it and from shitting in it.

 

[BoomerD]

1/10ths and 1/100ths are the standard way of measuring rainfall.

The Tru-Chek wedge is the gold standard for non weighing bucket rain gauges but they cost $30.

Tru-Chek® Direct-Reading Rain Gauge

One side is graduated from 0.01” to 6” while the other side ranges from 0.1 mm to 150 mm. This 13” long gauge is constructed of heavy, weather-resistant plastic with permanently marked graduations.

www.forestry-suppliers.com

Same problem. Needs a bird block.