3 decimeters is equal to 1 foot.

1 yard is equal to 9 decimeters.

Just multiply by 3

I’m 6 ft tall. If someone asks me how tall I am in metric, I just say 18 decimeters.

An American football field is 100 yards, or 300 feet. 900 decimeters.

An 8ft board is 24 decimeters

Really not that hard to convert. Sadly no one that uses the metric system uses decimeters for some reason.

A standard doorway in US is 3 ft. Has to be that for code. 91.4 cm or .91 meters. If you used 9 decimeters it would only be .5 inch off.

You round to 90 cm you’d be .5 inch off. If you round to .9 meters you’d be almost .5 inch off.

If the metic system was shown to the US as decimeters, they would be on board more.