Thank you. Good morning, and again, I appreciate everybody participating today in Packaging Corporation of America's first quarter 2021 earnings release conference call. I'm Mark Kowlzan, Chairman and CEO of PCA. And with me on the call today is Tom Hassfurther, Executive Vice President, who runs our Packaging business; and Bob Mundy, our Chief Financial Officer. I'll begin the call with an overview of our first quarter results, and then turn the call over to Tom and Bob, who'll provide additional details. I'll then wrap things up and then we'd be glad to take questions. Yesterday we reported first quarter net income of $167 million or $1.75 per share.
First quarter net income included special items expenses of $0.02 per share related to closure costs for certain corrugated products facilities and specific costs related to discontinuing paper operations associated with the previously announced conversion of the No. 3 machine at our Jackson, Alabama mill to linerboard.
Excluding the special items, first quarter 2021 net income was $169 million or $1.77 per share compared to the first quarter 2020 net income of $143 million or $1.50 cents per share.
First quarter net sales were $1.8 billion in 2021 and $1.7 billion in 2020. Total company EBITDA for the first quarter, excluding special items, was $342 million in 2021 and $311 million in 2020. Details of the special items for both the first quarter of 2021 and 2020 were included in the schedules that were accompanying the earnings press release.
Excluding the special items, the $0.27 per share increase in first quarter 2021 earnings compared to the first quarter of 2020 was driven primarily by higher volumes of $0.45 and prices and mix $0.31 in the Packaging segment and lower annual outage expenses for $0.12. The items were partially offset by lower volumes, $0.28 and prices and mix of $0.03 in the Paper segment. Operating costs were $0.15 per share higher, primarily due to inflation-related increases, particularly in the areas of labor and benefits expenses, and fiber costs and energy.
We also had inflation-related increases in our converting costs, which were $0.02 per share higher.
For the last three quarters, freight and logistics costs have risen and were $0.12 per share higher in the first quarter compared to last year. Significant increases in fuel costs, tight truck supply and the higher mix of spot pricing to keep up with box demand are the primary drivers. And in the first quarter, we had the issues brought on by the winter storms as well.
We also had other expenses of $0.01 per share.
Looking at the Packaging business, EBITDA, excluding special items in the first quarter of 2021 of $352 million with sales of $1.6 billion resulted in a margin of 22% versus last year's EBITDA of $290 million and sales of $1.5 billion or a 20% margin. Demand in the Packaging segment remained very strong, as sales volume in both our containerboard mills and our corrugated products plants set or matched all-time quarterly records.
Although we were able to replenish some inventory during the quarter by utilizing the Jackson, Alabama mill for additional containerboard production, we again ended the period with inventory levels lower than planned and at record lows from weeks of supply standpoint due to stronger than expected demand.
Our mills and box plants displayed outstanding management of their operations to meet customer commitments, in spite of several weather-related events that impacted their operations, created raw material availability issues and presented both inbound and outbound freight and logistics challenges.
In addition, our facilities continued to deliver on numerous cost reduction initiatives, efficiency improvements and capital projects, and bringing the benefits of those efforts to the bottom line.
We also recently completed two high return strategic projects that we've mentioned to you before; the OCC project at our Wallula mill and the Boiler project at our Filer mill. The tremendous effort our employees put into these initiatives and projects helps us minimize some of the cost inflation we see every year and especially now with what we're seeing in the areas I mentioned previously. I'll now turn it over to Tom, who will provide more details on containerboard sales in our corrugated business.