There's a couple of convenience approximations I use to work with US Imperial..
30cm is a "metric foot" (it's actually even closer to 1 light nanosecond which is kinda cool for thinking about distances at computer speeds)
250ml is a "metric cup"
30cm is a "metric foot" (it's actually even closer to 1 light nanosecond which is kinda cool for thinking about distances at computer speeds)
250ml is a "metric cup"
Another "close enough" value is the binary inch of 25.6 mm. Makes dealing with /32s and /64s oh so much easier.
with all the handy halvings in between + higher granularity of ml.. 'course I'm usually approximating on a gramme scale anyway.
But for larger stuff I round up to 250.
It turns out that UK/US sizes are based on the length of a barley corn.
Quite why it isn’t just in centimetres is baffling. https://en.wikipedia.org/wiki/Shoe_size
Inches vs. centimeters? Baby stuff. Get on my level. :D