45 x 35 x 16 cm royal mail box

A standard Royal Mail postbox in the UK!

According to Royal Mail's specifications, the dimensions of a standard postbox are:

• Height: 45 cm (17.72 inches)
• Width: 35 cm (13.78 inches)
• Depth: 16 cm (6.3 inches)

So, yes, the dimensions you provided match the standard Royal Mail postbox design.