Container Slot Utilisation Calculator

Work out container slot utilisation instantly with clear inputs, formula shown and shareable results.

About Container Slot Utilisation Calculator

Slot utilisation counts every box on board against nominal capacity, but only laden boxes earn freight. Reporting both figures separates the operational fill from the commercial fill, and the empty share shows how much capacity is consumed repositioning equipment rather than carrying cargo.

Formula

Slot utilisation

utilisation = (laden + empty TEU) / nominal capacity; revenue utilisation uses laden TEU only

Worked example

With the default values below, Container Slot Utilisation Calculator returns Slot utilisation of 91.04%. Change any input above and every figure here is recalculated in your browser.

Inputs used

Nominal slot capacity: 4,800 TEU
Loaded TEU on board: 3,950 TEU
Empty TEU repositioned: 420 TEU
Reefer plugs used: 320 plugs

Results

Slot utilisation: 91.04% %
Revenue-earning utilisation: 82.29% %
Slots unused: 430 TEU
Empty share of slots used: 9.61% %

Step by step

1Values used
2Slot utilisation
3Slot utilisation= 91.04 %
4Revenue-earning utilisation= 82.29 %
5Slots unused= 430 TEU
6Empty share of slots used= 9.61 %

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Marine results are planning estimates only. Verify against the vessel's approved stability booklet, loading manual, class society rules and applicable maritime regulations before loading or sailing.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Marine results are planning estimates only. Verify against the vessel's approved stability booklet, loading manual, class society rules and applicable maritime regulations before loading or sailing.

Frequently Asked Questions

Why can a ship not always load to nominal capacity?

Weight limits, stability, reefer plug availability, stack weight limits and port rotation constraints usually bite before slots run out.

Why carry empties at all?

Trade imbalance leaves boxes where they are not needed, so repositioning empties is a cost of keeping equipment available in export regions.