BMW 3 Series (2015) is 231 mm (9.09 inch) longer and 24 mm (0.94 inch) wider than Mercedes B-Class (2018).
Mercedes B-Class (2018) is 128 mm (5.04 inch) higher, 170 kg (375 lbs) lighter and has 6 liters (0.21 ft3) bigger cargo space than BMW 3 Series (2015).
Size difference at a glance
BMW 3 Series (2015) is 5.3% longer than Mercedes B-Class (2018).
BMW 3 Series (2015) is 1.3% wider than Mercedes B-Class (2018).
BMW 3 Series (2015) is 8.2% lower than Mercedes B-Class (2018).
BMW 3 Series (2015) is 12.2% heavier than Mercedes B-Class (2018).
BMW 3 Series (2015) is 1.2% smaller in cargo space than Mercedes B-Class (2018).
Overall footprint
BMW 3 Series (2015) has a 6.7% larger overall footprint (length × width).
