A wedding, party or conference has a footprint like any other activity: guests travel, the venue uses energy, and everyone eats. Offsetting it means estimating those emissions, cutting what you can, and covering the rest with carbon credits that are retired. This page is part of our guide to offsetting.
Why guest travel matters most
Earlier studies of in-person conferences, reviewed in a 2021 paper in Nature Communications, all identified transport as the environmental hotspotSource 1. The authors’ own analysis found that moving from in-person to virtual conferencing could cut the carbon footprint by 94%Source 1. A wedding is smaller, but it has the same ingredients, and in the worked example below guest travel is most of the total.
That makes the estimate simpler than it looks. You don’t need every guest’s exact route; you need a rough idea of how many people are coming from how far, and how they’ll travel.
Matched shop
Buy portfolio credits
- Registry serial numbers
- Retirement certificate
- Project documentation
Four steps
Step 1: Estimate guest travel
Ask guests roughly where they’re coming from.
Step 2: Add venue and food
Energy use and catering.
Step 3: Cut what you can
Local venue, shuttle buses, less meat.
Step 4: Offset and share
Buy credits and share the retirement certificate.
Tip
Put the retirement certificate link on your event website — guests like seeing it.
A worked example
The table below is a made-up wedding of 100 guests, worked out with UK government emission factorsSource 2. Sixty guests drive 200 km each way, two to a petrol car; twenty take the train the same distance; twenty fly a 1,000 km short-haul route each way in economy; and the guests book 40 hotel room-nights. Swap in your own numbers.
Scrolls sideways to show every column.
| Item | Basis | Emissions (kg CO₂e) |
|---|---|---|
| 30 petrol cars, 400 km return | 0.16152 kg per car-km | 1,938 |
| 20 guests by national rail, 400 km return | 0.03092 kg per passenger-km | 247 |
| 20 guests flying short-haul economy, 2,000 km return | 0.12576 kg per passenger-km, incl. non-CO₂ effects | 5,030 |
| 40 hotel room-nights in the UK | 10.4 kg per room per night | 416 |
| Total | — | 7,632 |
As of Oct 2026 · Source: [2] DESNZ greenhouse gas conversion factors 2026
That is about 7.6 tonnes of CO₂e, or eight credits. The twenty guests who fly account for about two-thirds of it, which is why the choice of venue, and how far guests have to come, matters more than anything else you decide. For guests flying in, our flight emissions calculator gives a figure for any pair of airports. Keep a note of your assumptions, such as how many guests came by each mode, so you can show how you reached the total.
Venue and food
The venue’s energy use is harder to pin down, but ask for it if you want a complete figure. If the venue can tell you the electricity and gas it used on the day, you can convert it with the same factors as a home; our guide to offsetting home energy shows how.
Food matters more than people expect. A large UK study found that a day’s food on a medium-meat diet comes to about 7.0 kg CO₂e per person, against about 4.2 kg for a vegetarian diet and 2.5 kg for a vegan dietSource 3. Those figures are for a whole day’s eating, not one meal, but they show the direction: a menu with less meat has a smaller footprint.
Cut what you can first
The Oxford Offsetting Principles start with reducing emissions and treat credits as a complement for what remainsSource 4. For an event, that means:
- Choose a venue near most guests, and one that is easy to reach by train or coach. DESNZ puts a coach at about 0.039 kg CO₂e per passenger-kilometre, against 0.162 kg per kilometre for an average petrol carSource 2.
- Run shuttle buses from the nearest station instead of leaving everyone to drive.
- Serve less meat, or make the vegetarian option the default.
- Let distant guests join online for conferences and other events where that works.
Can guests pay for their own offsets?
Yes. You can cover the whole event yourself, or offset the venue and food and invite guests to offset their own trips. If you do that, share a link to a calculator and a seller, and say how you’ll show the result, for example by listing the retirement records on the event website.
One credit represents one tonne of CO₂eSource 5. Our credits calculator rounds a total up to whole credits and shows an estimated cost. Before you buy, check that the seller names the project, standard and registry; our guide to how to verify carbon credits shows what to look for.
Be careful with “carbon neutral event” labels
Claims: what an offset can and can't say
An event isn’t emission-free because credits were bought. US guidance says it is deceptive to imply that an offset represents reductions that have already happened or will happen soon if they won’t happen for two years or more, without saying so clearlySource 6. A factual line, such as “we retired 8 tonnes of verified credits for our guests’ travel” with a link to the registry record, says more than a label.
If your event involves a lot of flying, our guides to offsetting a flight and offsetting business travel go into more detail.