1. What is a Gross to Net Tonnage Calculator?

Definition: This calculator converts gross tonnage to net tonnage by accounting for non-cargo spaces in a vessel.

Purpose: It helps ship owners, operators, and maritime professionals determine the actual revenue-earning capacity of a vessel.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( NT \) — Net Tonnage (unitless)
• \( GT \) — Gross Tonnage (unitless)
• \( D \) — Deducted Volume (m³) of non-cargo spaces
• \( V \) — Total Volume (m³) of all enclosed spaces

Explanation: The formula calculates the proportion of a vessel's volume that can be used for cargo by subtracting non-revenue spaces.

3. Importance of Net Tonnage Calculation

Details: Net tonnage determines port fees, canal tolls, and regulatory compliance. It represents the vessel's earning capacity.

4. Using the Calculator

Tips: Enter the gross tonnage, deducted volume (non-cargo spaces), and total volume (all enclosed spaces). All values must be > 0 and deducted volume ≤ total volume.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between gross and net tonnage?
A: Gross tonnage measures total enclosed space, while net tonnage measures only revenue-earning space.

Q2: What spaces are typically deducted?
A: Engine rooms, crew quarters, navigation spaces, and other non-cargo areas.

Q3: How is this used in maritime operations?
A: Net tonnage determines port fees, canal tolls, and regulatory requirements.

Q4: Can net tonnage exceed gross tonnage?
A: No, net tonnage is always ≤ gross tonnage as it's a portion of the total.

Q5: Where can I find these values for my vessel?
A: They are calculated during vessel surveys and documented in the ship's tonnage certificate.