Your shipping system may provide aggregated distance and weight of all your shipments. DO NOT SIMPLY INPUT TOTAL MILES AND TOTAL TONS INTO YOUR WORKBOOK - this calculation effectively assumes your entire tonnage is transported on EACH AND EVERY truck, railcar, aircraft, or barge, and will clearly overstate your ton-miles.
The most accurate way to input your shipping data is to drop in each shipment weight, distance, and shipping mode into Scope 3.4 and 3.9 of your workbook. The BEE will then calculate ton-miles* for each shipment and sum those to find your total ton-miles by mode. An emission factor is then applied to the total ton-miles per shipment mode to equate to tons of carbon.
*Ton-miles are calculated by multiplying the weight and distance of a single shipment.
If you need to use aggregate shipping data you should determine your average payload (shipment weight) per carrier and the total miles per carrier. Input those numbers in the weight and distance columns of the workbook and attribute a mode to each carrier.