Every order you ship has a footprint: the trucks, vans, ships or aircraft that carry it from supplier to warehouse and from warehouse to customer. Offsetting shipping means estimating those emissions, cutting what you can, and retiring credits for the rest. This page is part of our guide to offsetting.
How are shipping emissions estimated?
Freight emissions are worked out per tonne-kilometre: the weight carried, in tonnes, times the distance, times an emission factor for the transport mode. The UK government publishes freight factors for vans, lorries, rail, cargo ships and freight flightsSource 1.
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| Mode | Factor (kg CO₂e per tonne-km) |
|---|---|
| Freight flight, long-haul (with non-CO₂ effects) | 0.89939 |
| Freight flight, short-haul (with non-CO₂ effects) | 1.27835 |
| Van, average up to 3.5 t, diesel | 0.63511 |
| Lorry (HGV), average, not refrigerated | 0.10356 |
| Freight train | 0.02583 |
| Container ship, average | 0.01612 |
As of Oct 2026 · Source: [1] DESNZ greenhouse gas conversion factors 2026
The spread is enormous. Per tonne-kilometre, a long-haul freight flight emits about 56 times as much as a container ship on these factorsSource 1. An average diesel van emits about six times as much per tonne-kilometre as an average lorrySource 1, which is why the last mile matters even though it is short.
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Buy portfolio credits
- Registry serial numbers
- Retirement certificate
- Project documentation
A worked example
Take a made-up 2 kg parcel shipped 10,000 km from a supplier overseas, then 300 km by lorry to a warehouse and 100 km by van to the customerSource 1:
- By sea: 0.002 t × 10,000 km × 0.01612 = about 0.32 kg CO₂e.
- By air instead: 0.002 t × 10,000 km × 0.89939 = about 18 kg CO₂e.
- Lorry leg: 0.002 t × 300 km × 0.10356 = about 0.06 kg CO₂e.
- Van leg: 0.002 t × 100 km × 0.63511 = about 0.13 kg CO₂e.
By sea, the parcel’s whole journey comes to about 0.5 kg CO₂e, so 10,000 such orders a year would be about 5.1 tonnes, or six credits. If the goods came by air, the same orders would be about 182 tonnes. How goods are moved matters far more than the number of credits you buy.
You won’t know the exact route of every parcel. Group orders by destination region and typical mode, use road distances for lorry and van legs, and write down your assumptions so the estimate can be checked and updated next year.
Which scope is shipping?
Under the GHG Protocol, outbound delivery that you pay for, for example through a courier or a fulfilment service, counts in scope 3, category 4 (upstream transportation and distribution)Source 2. Transport after the sale that you don’t pay for is category 9 (downstream transportation and distribution)Source 2. Fuel for vehicles you own or control is scope 1Source 2. Our page on scope 1, 2 and 3 emissions explains the categories.
If your carriers send emissions reports, use their figures for the legs they cover; they can be more specific than average factors.
Cut what you can first
The Oxford Offsetting Principles start with reducing emissions and treat credits as a complement for what remainsSource 4. For shipping, the biggest levers are:
- Move inbound stock from air to sea or rail. On the factors above, this is by far the largest cut available.
- Consolidate orders into fewer, fuller shipments, and avoid express options that require air freight.
- Cut packaging weight, since emissions scale with weight.
- Reduce returns with better product information and sizing.
- Choose carriers with electric vans for the last mile where they operate. DESNZ’s average battery electric van factor is under a quarter of the diesel one per tonne-kilometreSource 1.
How to offset shipping, step by step
Step 1: Gather shipping data
Export a year of shipments with weight, origin, destination and transport mode, or ask your carriers for emissions reports.
Step 2: Convert to tonnes of CO₂e
Multiply weight in tonnes by distance in kilometres and an emission factor per tonne-km for each leg, then add up the legs.
Step 3: Cut what you can
Move inbound stock from air to sea, consolidate orders, reduce packaging weight and cut returns.
Step 4: Work out how many credits you need
One credit covers one tonne of CO₂e, so round the yearly total up to whole credits.
Step 5: Buy from a seller you can check
Choose a seller that names the project, standard and registry before you pay.
Step 6: Report it accurately
Keep shipping in your scope 3 inventory and describe the credits you retired as a separate contribution.
One credit represents one tonne of CO₂eSource 5. Our credits calculator rounds a total up and shows an estimated cost. The small business buying guide covers how to buy in batches and what to ask a seller.
Be careful with “carbon neutral delivery”
Claims: what an offset can and can't say
From 27 September 2026, EU consumer law bans claims that a product has a neutral, reduced or positive impact on the environment in terms of greenhouse gas emissions because of offsettingSource 3. That rules out “carbon neutral delivery” badges based on credits for shoppers in the EU. Companies with science-based targets also can’t count credits as reductionsSource 6. Say what you measured, what you cut and how many tonnes of credits you retired, with a link to the registry record. Our guide to the EU green claims ban has examples.
Shipping is often only part of an online shop’s footprint. See also how to offset a website and how to offset business travel.