A copper fels, ("kopparstyver" på svenska) is the same as a copper piece (CP) from 5e or ACKS.

A dirham was made of silver. They're the same as a silver piece (SP) from 5e or ACKS, or a copper piece (CP) from LotFP. (Because LotFP fucked up their money.)

A dinar was made out of gold. They're the same as a gold piece (GP) from 5e or ACKS, or a silver piece (SP) from LotFP.

On Earth, copper fels weighed between five and six grams, and dirham and dinars both weighed 4.3 grams. This is in line with what ACKS suggests, but we instead follow the 5e PHB where they weigh 0.02 pounds. That's twice as much as on Earth, but… coins are tricky to carry.

You can't easily make exchanges between coppers, dirhams and dinars. Especially now that Setara bint Aasim is dead. You can think of them as roughly 100 coppers to 10 dirhams to 1 dinar. But some merchants value silver higher, or lower.