1. What is Net Tonnage?

Net Tonnage (NT) is a dimensionless index calculated from the moulded volume of all cargo spaces of a ship. It represents the useful volume of a ship and is used to assess fees and taxes for commercial vessels.

2. How Does the Calculator Work?

The calculator uses the Net Tonnage formula:

Where:

• \( NT \) — Net Tonnage (tons)
• \( M \) — Multiplier (dimensionless)
• \( GT \) — Gross Tonnage (tons)

Explanation: The formula calculates the net tonnage by multiplying the multiplier factor (M) with the gross tonnage (GT) of the vessel.

3. Importance of Net Tonnage Calculation

Details: Net tonnage is crucial for determining port dues, canal transit fees, and other marine charges. It's also used for regulatory compliance and vessel classification.

4. Using the Calculator

Tips: Enter the multiplier (M) as a dimensionless value and gross tonnage (GT) in tons. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between net and gross tonnage?
A: Gross tonnage represents the total internal volume of a ship, while net tonnage represents the useful volume available for cargo.

Q2: How is the multiplier (M) determined?
A: M is calculated based on the vessel's characteristics and is typically between 0.22 and 0.32 for most ships.

Q3: What are typical net tonnage values?
A: Values vary widely by vessel type, from small boats with NT < 100 to large container ships with NT > 50,000.

Q4: Is net tonnage the same as deadweight tonnage?
A: No, deadweight tonnage measures weight-carrying capacity, while net tonnage measures volume.

Q5: Where can I find M and GT values for a ship?
A: These values are typically found in the ship's tonnage certificate or International Tonnage Certificate (ITC).