Shipping Emissions Calculator Formula

Understand the math behind the shipping emissions calculator. Each variable explained with a worked example.

Use the Shipping Emissions Calculator

Formulas Used

Shipping CO2

co2_kg = co2_lbs / 2.205

Shipping CO2 (lbs)

co2_lbs_out = co2_lbs

Emission Intensity

intensity = co2_lbs / weight_lbs

Variables

VariableDescriptionDefault
weight_lbsPackage Weight(lbs)10
distance_milesShipping Distance(miles)1000
mode_factorTransport Mode Factor(lbs CO2/ton-mile)0.37
weight_tonsDerived value= weight_lbs / 2000calculated
co2_lbsDerived value= weight_tons * distance_miles * mode_factorcalculated

How It Works

How to Calculate Shipping Emissions

Shipping emissions depend on weight, distance, and transport mode.

Mode Factors (lbs CO2 per ton-mile)

  • Truck: ~0.37
  • Rail: ~0.05
  • Ocean Ship: ~0.01
  • Air freight: ~2.2

    • Formula

    CO2 = (Weight / 2000) * Distance * Mode Factor

    Worked Example

    Ship a 10-lb package 1,000 miles by truck.

    weight_lbs = 10distance_miles = 1000mode_factor = 0.37
    1. 01Weight in tons: 10 / 2000 = 0.005 tons
    2. 02CO2: 0.005 * 1000 * 0.37 = 1.85 lbs
    3. 03In kg: 1.85 / 2.205 = 0.84 kg CO2

    Frequently Asked Questions

    Which shipping mode produces the least emissions?

    Ocean shipping at about 0.01 lbs CO2 per ton-mile, followed by rail at 0.05. Air freight is most intensive at 2.2.

    How do I pick the right mode factor?

    Use Truck = 0.37, Rail = 0.05, Ocean = 0.01, Air = 2.2 lbs CO2 per ton-mile. For mixed-mode shipping, use a weighted average.

    Does expedited shipping produce more emissions?

    Yes. Expedited shipping often uses air freight, producing 6x more CO2 than truck and 40x more than rail per ton-mile.

    Ready to run the numbers?

    Open Shipping Emissions Calculator