The flag of the British Virgin Islands has an aspect ratio of 1:2. It is a defaced Blue Ensign with the Union Jack in the canton (upper hoist-side quadrant) and the territory's coat of arms on the right side of the field.

Colors:

• Blue background: Pantone 280 C (#012169)
• Union Jack colors: Red (Pantone 186 C, #C8102E) and White (#FFFFFF)

Geometric properties:

• Union Jack dimensions: 3/5 of the flag's width and 1/2 of the flag's length
• Coat of arms: Positioned in the fly half of the flag, centered both vertically and horizontally

Measurements: Assuming the flag's width (W) and length (L), the measurements can be described as follows:

• Width (W): 1 unit
• Length (L): 2 units
• Union Jack: Width = 3/5 W, Length = 1/2 L
• Coat of arms: Centered within the remaining space on the fly half

Other relevant information:

• The coat of arms features a shield with Saint Ursula and twelve oil lamps, a helmet, mantling, and a scroll with the Latin motto "Vigilate" (Be Watchful).