Apr 28, 2021 · The amount of coal in an average railcar was assumed to be 100.19 short tons, or 90.89 metric tons (Hancock 2001). Calculation. Note: Due to rounding, performing the calculations given in the equations below may not return the exact results shown. 20.85 mmbtu/metric ton coal × 26.09 kg C/mmbtu × 44 kg CO 2 181.29 metric tons CO 2 /railcar