What is O/F? How to calculate ocean freight costs

O/F (Ocean Freight) is the sea freight charge for the transport leg covered by the quotation. Understanding O/F correctly helps businesses calculate ocean freight costs, compare shipping options, and budget more accurately.

However, O/F is usually only one component of the total logistics cost. The article below from 3W Logistics explains what O/F is, how to calculate freight for full container loads and LCL shipments, and what to check before confirming a booking.

1. What Is O/F? Distinguishing It from Total Ocean Freight Costs

O/F stands for Ocean Freight, commonly referred to as sea freight. On a quotation, this line item represents the cost of transporting goods by sea between ports, or within the agreed service scope. Some carriers use the terms Ocean Base Rate or Basic Ocean Freight for the base freight component.

When enquiring about ocean freight costs, businesses need to clarify whether they are asking about O/F alone or the total cost of delivering goods to their desired destination. With the same O/F rate, the total amount payable can vary due to surcharges, port charges, and inland transport costs.

Note: An “all-in” quotation must clearly state which leg it covers and what it includes. Do not assume it means door-to-door delivery or that destination charges are included.

2. What Units Are Used to Calculate Ocean Freight Costs?

The unit of measure for ocean freight costs depends on the shipping method. For containerised cargo, the two most common options are FCL (Full Container Load) and LCL (Less than Container Load).

• FCL cargo: typically quoted in USD per container, broken down by container type – 20-foot, 40-foot, 40-foot high cube, or specialised equipment.
• LCL cargo: typically charged on a W/M (Weight or Measurement) basis, comparing gross weight against volume and applying whichever yields the higher chargeable unit.
• Bulk and project cargo: may be calculated per tonne, by volume, per cargo unit, or under a charter arrangement; specific conditions must be applied.

Note: FCL is priced per container, whereas LCL requires a comparison between weight and volume. A single formula therefore cannot be applied to every shipment.

3. How to Calculate Ocean Freight Costs for FCL Shipments

For full container loads, the O/F component of the ocean freight cost is determined by the number of containers and the applicable unit rate:

FCL O/F = Sum of (Number of containers of each type × O/F rate for that container type).

Worked example: A business ships 2 × 20-foot containers and 1 × 40-foot high cube container. Assuming an O/F rate of USD 600 per 20-foot container and USD 950 per 40-foot high cube:

• Freight for 2 × 20-foot containers: 2 × 600 = USD 1,200.
• Freight for 1 × 40-foot high cube: 1 × 950 = USD 950.
• Total O/F: 1,200 + 950 = USD 2,150.

These figures are illustrative examples for calculation purposes only and do not represent current market rates. The result does not include any charges outside O/F that may be billed separately.

When calculating ocean freight costs for FCL shipments, always check the equipment code and weight conditions. Do not assume a 40-foot container costs twice a 20-foot container; refrigerated cargo, dangerous goods, and out-of-gauge cargo must each be quoted separately.

4. How to Calculate Ocean Freight Costs for LCL Shipments

4.1. Calculating cargo volume in CBM

CBM (Cubic Metre) is the standard volume unit. For identical cartons:

Volume (CBM) = Length (m) × Width (m) × Height (m) × Number of cartons.

For mixed dimensions, calculate each group separately and add them together. Always use the outer dimensions after packing; cargo on pallets must include the pallet height and any overhang.

4.2. Comparing volume and weight to determine the W/M unit

To calculate ocean freight costs on a W/M basis, quotations typically apply a conversion ratio of 1 CBM = 1,000 kg. Using this ratio:

Chargeable units = The higher of: Total CBM vs Total gross weight (kg) ÷ 1,000.

LCL O/F = Chargeable units × O/F rate per W/M.

Businesses must always verify the conversion ratio, minimum charge thresholds, and rounding rules stated on the specific quotation.

4.3. Worked examples for light and heavy cargo

Assuming an O/F rate of USD 50 per W/M, a conversion ratio of 1 CBM = 1,000 kg, and no minimum charge or other adjustments affecting the two shipments below:

Both shipments have the same volume, yet the ocean freight costs differ because Shipment B has a higher chargeable weight. The rates of USD 50/W/M, USD 60, and USD 100 are for illustration purposes only and do not include any charges outside O/F.

Note: Do not add CBM and tonnes together. With a W/M quotation as described above, select the higher value. If a small shipment is subject to a minimum charge or a non-stackable surcharge, these must be calculated separately in accordance with the confirmed conditions.

5. Surcharges to Check Outside of O/F

To budget accurately for ocean freight costs, the O/F must be separated from additional charges. Not every shipment will attract all of the following fees:

To avoid double-counting when calculating ocean freight costs, only add charges that are not already included in the agreed price:

Budget for agreed service scope = O/F + Surcharges not already included + Origin/destination charges within the payer’s responsibility + Any additional services requested.

6. Factors That Affect Ocean Freight Costs

Ocean freight costs are not fixed across all trade lanes or at all times. When comparing quotations, keep the following information consistent:

• Port of loading, port of discharge, and routing: even within the same country, different ports or the choice between direct service and transshipment can result in different rates.
• Cargo type and equipment: general cargo, refrigerated goods, dangerous goods, and out-of-gauge cargo each require different transport conditions.
• Cargo quantity: number of containers, gross weight, packed dimensions, and stackability all influence the pricing method.
• Cargo ready date and vessel capacity: the shipping schedule must align with available vessel space and equipment.
• Service scope: a port-to-port rate differs from a door-to-door rate.
• Rate validity and currency: verify the applicable conditions, adjustable surcharges, and the exchange rate at the time of payment.

In any quotation, the trade lane scope, validity period, and items marked “inclusive” are key details to cross-check. This prevents using an expired quotation or adding a charge that is already included.

7. Who Pays Ocean Freight Costs?

Responsibility for ocean freight costs must be determined by reference to the sales terms and the contract. Under the common sea freight conditions of Incoterms® 2020:

• FOB: the buyer typically arranges and pays the main carriage freight from the port of loading.
• CFR: the seller contracts and pays freight to the named port of destination.
• CIF: the seller pays freight to the named port of destination and arranges insurance under the applicable terms.

On shipping documents, Freight Prepaid indicates that freight has been paid at the origin, while Freight Collect indicates that freight is to be collected at the destination under the agreed transport arrangement. Always read the scope of the freight amount recorded; these two terms cannot be used to infer the full cost allocation between buyer and seller.

8. How to Request a Quotation and Optimise Ocean Freight Costs

Step 1: Prepare shipment information

Provide the cargo name, port of loading, port of discharge, cargo ready date, and delivery terms. For FCL, add the container type and quantity; for LCL, provide the number of packages, dimensions, total CBM, gross weight, and stackability.

Step 2: Request an itemised quotation

Ask for O/F, surcharges, origin charges, destination charges, and inland costs to be shown separately. An ocean freight quotation should state the unit of measure, currency, validity period, exclusions, and payment terms.

Step 3: Compare on the same service scope

Compare total costs for the same trade lane and service level, taking into account estimated transit time, vessel schedule, and free time allowances. For LCL cargo, it may be worth requesting an FCL option to compare total costs; do not apply a single fixed CBM threshold across all trade lanes.

Step 4: Confirm the rate and manage additional charges

Before booking, confirm the rate applicable to the specific shipment, the cargo cut-off date, document submission deadlines, and the conditions for amendments or cancellations. Plan for timely cargo collection, customs clearance, and container return to minimise storage costs.

A practical perspective: A low O/F rate alone is not sufficient to conclude that an option is cost-effective. Businesses should verify the total amount payable, destination charges, and free time conditions before making a decision.

FAQ – Frequently Asked Questions About Ocean Freight Costs

Question 1: Is O/F the total cost of shipping?

Generally not. O/F is the sea freight charge within the quoted scope; the total cost may include additional surcharges, Local Charges, inland transport, and other services. Always check the list of included and excluded items.

Question 2: Are ocean freight costs calculated by kg or by CBM?

FCL cargo is generally charged per container. LCL cargo is typically charged on a W/M basis: compare the CBM against the gross weight converted using the ratio stated on the quotation, select the higher value, and apply any minimum charge if applicable.

Question 3: For LCL cargo under 1 CBM, is the actual volume charged?

It depends on the quotation. If the carrier applies a minimum of 1 W/M, a small shipment may still be charged at that minimum. Some documentation or handling fees are also billed separately per shipment.

Question 4: Can a single ocean freight rate schedule be used for a full year?

Only under an appropriate agreement covering the validity period and pricing mechanism. Spot quotations typically have a limited validity; long-term contracts also require verification of which components are fixed and which are subject to adjustment.

Question 5: Is FCL always cheaper than LCL?

No. LCL may be the right choice for small shipments, while FCL becomes worth comparing as cargo volume increases or where specific requirements apply. The decision should be based on total cost, cargo characteristics, and the actual delivery schedule.

Question 6: What information is needed to receive an ocean freight quotation?

At a minimum: cargo name, port of loading, port of discharge, intended shipment date, and cargo quantity. Add container type for FCL; carton dimensions, total CBM, and gross weight for LCL. Provide the pickup or delivery address if door-to-door service is required.

To receive tailored advice and an ocean freight quotation, businesses are welcome to send their shipment details to 3W Logistics through the contact channels below.

How Does 3W Logistics Support Export Ocean Freight?

With years of experience in freight forwarding and registration as an OTI-NVOCC with an FMC bond (Federal Maritime Commission) in the United States, 3W Logistics is committed to providing transparent, fully inclusive quotations from the outset, helping businesses take confident control of their export shipping costs.

End-to-end logistics services at 3W Logistics:

• Export ocean freight (FCL/LCL): Transparent all-in quotations covering all applicable surcharges, with no unexpected costs.
• Export customs declaration: Efficient documentation processing to minimise container and storage detention charges.
• Export procedure advisory by commodity: Identifying the correct specialised documents required before goods reach the port.
• C/O and specialised documentation support: Fumigation, phytosanitary and animal health certificates – reducing documentation preparation time.

Why choose 3W Logistics for your export shipment? Because export shipping costs involve multiple surcharges that fluctuate by carrier and season, businesses need a partner that provides transparent, comprehensive quotations from day one so they can plan their budget with confidence. Contact 3W Logistics for a detailed quotation for your export shipment.

Ms. Apple (CCO)

Ms. Apple is the CCO (Chief Commercial Officer) at 3W Logistics, with over 10 years of experience in sales and business operations management.

At 3W Logistics, Ms. Apple is responsible for commercial strategy, corporate customer development, managing a team of more than 50 sales professionals, and improving business performance in the logistics sector.

With practical experience in sales management and market development, Ms. Apple shares professional insights on business logistics solutions, international transportation, freight forwarding, customer management, trade lane development, and growth strategies in the logistics industry.