Cillar | Flight Emissions Calculator

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Distances are calculated as great-circle plus a fixed routing uplift, per standard aviation emissions methodology.

Departure airport

Arrival airport

Cabin class

Passengers

Trip type

Reference / traveller / purpose (optional)

Emission factors & methodology settings

Include indirect (non-CO₂) effects — DEFRA recommended default Applies the published "including indirect effects of non-CO₂ emissions" factor set (approx. a 70% uplift on CO₂ alone, to approximate contrails, NOₓ and high-altitude water vapour effects). DEFRA's own guidance is that organisations should generally use this set. Uncheck to use "direct effects only" instead — check which your target disclosure framework or auditor expects, as conventions vary. Include Well-to-Tank (WTT) emissions Upstream emissions from extracting, refining and transporting jet fuel. UK Government guidance reports this separately (often mapped to Scope 3 Category 3 rather than Category 6), but many institutions include it alongside travel for a "well-to-wheel" total. Shown as its own line either way so it can be excluded from your Category 6 figure if needed.

Source: UK Government GHG Conversion Factors for Company Reporting, 2026 edition — "Business travel– air" and "WTT– business travel– air" worksheets, cross-checked against the accompanying methodology paper. Next official update: June 2027. Because domestic/short-haul/long-haul bands are defined relative to the UK, this tool auto-selects the correct DEFRA category per route (see each flight's label) rather than banding by raw distance — the applied category and factor are logged per flight below and in the CSV export for audit purposes.

Reporting output

Scope 3, Category 6 — Business Travel (Air). Figures update as flights are added.

Flight	Distance	CO₂e

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Methodology notes

Standard applied: GHG Protocol Corporate Value Chain (Scope 3) Standard, Category 6 — Business Travel. Emission factors are taken directly from the UK Government GHG Conversion Factors for Company Reporting, 2026 edition ("Business travel – air" and "WTT – business travel – air" worksheets), the dataset most GHG assurance providers and CDP/PRME-aligned university disclosures reference for flight emissions. Next official update: June 2027 — this tool should be re-checked against that release.
Distance: great-circle distance between airport coordinates × 1.08, the 8% uplift DEFRA specifies to account for indirect routing, holding and non-direct taxiing (current methodology paper, §8.37–8.38).
Band selection is UK-relative, not distance-relative. DEFRA's Domestic / Short-haul / Long-haul bands are only defined for flights touching the UK. Since Stellenbosch University's flights are almost all non-UK routes, this tool automatically applies:
- International, to/from non-UK — for any route where neither airport is in the UK and the two airports are in different countries (the correct DEFRA category for the great majority of university travel, e.g. Cape Town–Frankfurt, Cape Town–Dubai).
- Domestic, to/from UK (proxy) — for routes within a single non-UK country (e.g. Cape Town–Johannesburg). DEFRA has no published domestic band for South Africa specifically; this is the closest available published proxy and is flagged with a ⚑ on each such flight so it can be reviewed.
- Short-/Long-haul, to/from UK — only applied on the rare flight actually touching a UK airport, using DEFRA's own Europe/North-Africa-vs-rest-of-world definition.
Indirect (non-CO₂) effects: DEFRA publishes two parallel factor sets — with and without an uplift (roughly 70% higher) approximating contrails, NOₓ and high-altitude water vapour effects. DEFRA's guidance is that most reporters should use the "including indirect effects" set by default (this tool's default); switch it off only if your specific reporting framework requires direct CO₂/CH₄/N₂O only.
WTT (Well-to-Tank): shown as a separate line since it covers upstream fuel production/refining emissions, which some frameworks place under Scope 3 Category 3 rather than Category 6 — decide with your reporting team whether to fold it into the Category 6 figure or report it separately.
Audit trail: the CSV export logs the DEFRA band applied, whether it was a proxy, the exact factor values used, distance, and a timestamp per flight, so every figure can be traced back to source.