How to Calculate Air and Ocean Freight Charges

Freight pricing feels complicated because the number you first see is rarely the number you end up paying. The practical way to estimate accurately is to break charges into a repeatable structure, then apply the correct billing basis for each mode.

This guide explains the calculation logic your pricing team uses to build quotes and includes worked examples you can reuse.

Part 1: How air freight charges are calculated

Step 1) Determine actual vs volumetric weight

Air freight is priced using both actual weight and volumetric weight because airlines charge for space consumption as well as weight.

Step 2) Calculate volumetric weight

Use the standard formula:

volumetric weight (kg) = length (cm) × width (cm) × height (cm) ÷ 6,000

Example: 100 × 80 × 60 ÷ 6,000 = 80 kg.

Step 3) Calculate chargeable weight

Air is billed on chargeable weight, which is the higher of actual and volumetric weight.

chargeable weight = max(actual weight, volumetric weight)

Step 4) Calculate base air freight cost

base freight cost = chargeable weight × rate per kg

Step 5) Add surcharges and fixed fees

Base freight is only part of the total. Common add-ons include fuel surcharge, security surcharge, airport handling, documentation, customs clearance, and peak season or capacity surcharges.

If you want to standardize how your team stores and applies these items, align your process with a consistent quote structure using quote management overview.

Worked air example you can reuse

Assume:

• chargeable weight: 80 kg
• base rate: $4.50 per kg
• fuel surcharge: $0.60 per kg
• security surcharge: $0.20 per kg
• handling fees: $75 flat

Calculation:

• base freight: 80 × 4.50 = $360
• fuel: 80 × 0.60 = $48
• security: 80 × 0.20 = $16
• handling: $75

total air freight cost = $499

Practical tip: volumetric weight is often the surprise. Light but bulky cargo can price higher than expected, so packaging optimization can materially reduce cost.

Part 2: How ocean freight charges are calculated

Step 1) Start with the full cost stack

Ocean pricing is rarely just the main ocean rate. A typical structure is:

main ocean freight + origin charges + destination charges + surcharges + optional services

Optional services can include pickup, delivery, customs, warehousing, and insurance.

Step 2) Choose mode: FCL vs LCL

• FCL: you book a full container and pay a base rate per container type, then add local charges and surcharges.
• LCL: you share container space and pricing commonly uses a chargeable unit method such as W/M.

Step 3) For LCL, calculate CBM and W/M

LCL commonly uses W/M (weight or measure) where you pay based on whichever is higher:

• volume in CBM, or
• weight in metric tons (1,000 kg = 1 ton)

chargeable W/M = max(CBM, weight in tons)

CBM formula:
CBM = length (m) × width (m) × height (m) × number of cartons

Example: 10 cartons, each 0.60 × 0.40 × 0.50 m

• CBM per carton = 0.12
• total CBM = 1.20

If total weight is 650 kg = 0.65 tons:

• chargeable W/M = max(1.20, 0.65) = 1.20 W/M

If the LCL ocean rate is $85 per W/M:

• base ocean freight = 1.20 × 85 = $102

Step 4) Add the main cost components

Most ocean quotes break into these buckets:

• origin charges (export side): documentation, terminal handling, CFS handling for LCL
• destination charges (import side): destination terminal fees, deconsolidation, release fees
• carrier surcharges: lane and carrier dependent
• time-related fees: demurrage, detention, and per diem if cargo or equipment sits too long

To keep these consistent across reps and offices, many teams define charge categories and rules centrally, then apply them via templates and controlled logic. A good starting point is how velocity works.

Worked ocean examples you can reuse

Example A: LCL total estimate structure
Assume:

• chargeable W/M: 1.20
• ocean freight: $85 per W/M
• origin charges: $65
• destination charges: $95
• surcharges: $18 per W/M

Calculation:

• base ocean freight: 1.20 × 85 = $102
• surcharges: 1.20 × 18 = $21.60
• origin: $65
• destination: $95

estimated total = $283.60 (excluding duties, taxes, and inland trucking)

Example B: FCL total estimate structure
Assume:

• 40HC base ocean freight: $2,450 per container
• origin THC and docs: $420
• destination THC and local fees: $520
• surcharges: $180 per container

estimated total = $3,570 (excluding duties, taxes, and inland trucking)

The quoting layer that prevents mistakes

The formulas are the easy part. Most pricing mistakes happen in these areas:

1) Units and basis mismatch

Per kg vs per shipment, per container vs per W/M, and mixed minimums. Lock your basis per charge type and validate it at quote build time.

2) Incomplete scope

Port-to-port presented as door-to-door, or missing accessorials like pickup, delivery, customs, and insurance. Define scope clearly and treat add-ons as explicit line items.

3) Multi-currency inconsistencies

Different conversion timing and rounding rules can create totals that do not reconcile. A clean model is to store source currency, convert at quote-time, and lock the FX snapshot used for the quote. Use currency and exchange rates to standardize how your team approaches FX in quoting.

4) Revisions without governance

If weight, CBM, accessorials, or surcharges change, customers need clear versioning and deltas. Use quote revisions and version history to keep changes auditable and consistent.

Conclusion

To bring this full circle, this is exactly where Velocity helps pricing and ops teams move faster without sacrificing accuracy. By centralizing how you store rate inputs, standardizing charge categories, and enforcing consistent rules for air chargeable weight and ocean LCL W/M calculations, you can generate quotes that are repeatable, auditable, and easier to revise when weights, CBM, or surcharges change. If you want to operationalize this, align your workflow with quote management overview and govern changes with quote revisions and version history so every update is clear to both your team and the customer.