The dimensions of a standard 55-gallon barrel may vary slightly depending on the manufacturer, but the following are the approximate measurements:

- Height: 34 inches (86.4 centimeters)

- Diameter: 24 inches (61 centimeters)

- Volume: 55 US gallons (208.2 liters)

Please note that these measurements are for a standard 55-gallon barrel and may differ for barrels of different capacities.