Climate & Environment

Flight Emissions Calculator

What this does

Estimate the CO₂e of a flight from its one-way distance and cabin class, including a round-trip figure and an indicative offset cost.

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Calculator inputs

How to use it

Using the flight emissions calculator

  1. 01

    Find the great-circle distance

    Enter the one-way distance between origin and destination in kilometres; flight-distance sites or mapping tools give the straight-line figure.

  2. 02

    Pick your cabin class

    Economy is the baseline; premium cabins multiply emissions because they occupy more aircraft space.

  3. 03

    Read one-way, round trip and offsets

    The primary number is one-way; rows below double it for round trips and price an indicative offset at $20 per tonne.

Good to know

Why long-haul is cheaper per kilometre

Take-off, climb and landing burn fuel disproportionately. Spread over 8,000 km, that overhead becomes marginal; hence the lower long-haul factor. Two medium flights usually emit more than one direct flight of the same total distance.

The cabin-class effect is real

A business seat occupies two to four times the floor area of an economy seat, so its allocated share of the aircraft’s fuel is proportionally larger. Flying business long-haul can emit as much as several months of average driving.

About offsets

Voluntary carbon-market prices range from a few dollars to over $100 per tonne depending on project quality. The $20 figure here is a mid-range indicative price for budgeting, not an offer or endorsement.

How it's calculated

The math behind this calculator

CO₂e = distance × pkm-factor × cabin-multiplier pkm factor = 0.15 kg/km ≤ 3,700 km, else 0.11 kg/km

Emissions scale with passenger-kilometres: distance times a per-passenger factor that drops for long-haul flights because take-off and climb are amortised over more distance. We apply 0.15 kg CO₂e/pkm up to 3,700 km and 0.11 beyond; rounded DEFRA-style economy factors.

Cabin class multiplies the base figure: premium economy ≈ 1.6× and business ≈ 3× economy, reflecting the larger space (and fuel share) each premium seat occupies.

The offset row prices the one-way tonnage at $20 per tonne, an indicative voluntary-market price rather than a quote.

Assumptions & limitations

  • Economy-equivalent factors: 0.15 kg CO₂e/passenger-km short-haul, 0.11 long-haul (boundary 3,700 km).
  • Premium economy multiplier 1.6×; business 3×.
  • Radiative forcing at altitude is not included, so true climate impact may be higher than shown.
  • Offset pricing at $20/tonne is indicative only; voluntary-market prices vary widely.

Worked example

A 1,500 km one-way hop in economy emits about 225 kg of CO₂e; 450 kg round trip, with an indicative offset cost near $4.50 at $20 per tonne.

FAQ

Frequently asked questions

Where do I find my flight distance?
Use any great-circle distance mapper with the two airport codes. Distances under 3,700 km count as short-haul here; longer routes use the lower long-haul factor.
Do these numbers include contrails and radiative forcing?
No. Non-CO₂ effects at cruise altitude can roughly multiply aviation’s climate impact. These figures cover CO₂e only, consistent with DEFRA-style reporting before uplifts.
How accurate are the cabin multipliers?
They mirror widely used government factors (roughly 1.6× premium economy, 3× business). Actual allocation depends on the airline’s configuration and load factor.
Is $20 per tonne what offsets actually cost?
It is an indicative market price for mid-quality projects. High-durability removals can cost far more; cheap avoidance credits trade lower. Shop carefully.

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