You can carry cologne bottles of up to 3.4 oz actual size or less per item in your hand luggage.
For those with questions like, “Can I bring a bigger cologne bottle on a plane?” packing them in your checked luggage is the way to go.
Duty-free cologne and duty-free perfume are also sometimes more affordable due to the lack of customs duty and other taxes.
If you travel frequently, I highly recommend investing in a travel-size cologne. This needs to be under 100ml or 3.4 oz to take it in your hand luggage.