Actually, you rounded down
4.546 imperial and 3.785
Thats actually an issue with imperial units, they are not consistent. The American imperial units date back to the 18th Century, where as the British system was refined and defined in 1824, after our American cousins, had a bit of a tif (about tea) and went off on their own .
So that adds to even more confusion.
1UK pint = 0.83 US pints
1UK Gallon = 0.83 US Gallons
1 Swedish (Scandinavian) Mile = 10km
1 UK (US) mile = 1.6km
So be careful if a Scandinavian tells you the pub is a mile walk up the road!