Arch Coal (NYSE: ACI) reported earnings on May 1. Here are the numbers you need to know.

The 10-second takeaway
 For the quarter ended March 31 (Q1), Arch Coal missed estimates on revenues and missed expectations on earnings per share.

Compared to the prior-year quarter, revenue increased significantly and GAAP earnings per share dropped significantly.

Margins shrank across the board.

Revenue details
 Arch Coal reported revenue of $1.04 billion. The 13 analysts polled by S&P Capital IQ expected a top line of $1.13 billion on the same basis. GAAP reported sales were 19% higher than the prior-year quarter's $872.9 million.

Source: S&P Capital IQ. Quarterly periods. Dollar amounts in millions. Non-GAAP figures may vary to maintain comparability with estimates.

EPS details
 EPS came in at -$0.04. The 22 earnings estimates compiled by S&P Capital IQ forecast $0.20 per share. GAAP EPS of $0.01 for Q1 were 97% lower than the prior-year quarter's $0.34 per share.

Source: S&P Capital IQ. Quarterly periods. Non-GAAP figures may vary to maintain comparability with estimates.

Margin details
 For the quarter, gross margin was 18.2%, 690 basis points worse than the prior-year quarter. Operating margin was 4.9%, 680 basis points worse than the prior-year quarter. Net margin was 0.1%, 630 basis points worse than the prior-year quarter.

Looking ahead
 Next quarter's average estimate for revenue is $1.14 billion. On the bottom line, the average EPS estimate is $0.19.

Next year's average estimate for revenue is $4.57 billion. The average EPS estimate is $0.79.

Investor sentiment
 The stock has a four-star rating (out of five) at Motley Fool CAPS, with 1,487 members out of 1,552 rating the stock outperform, and 65 members rating it underperform. Among 345 CAPS All-Star picks (recommendations by the highest-ranked CAPS members), 334 give Arch Coal a green thumbs-up, and 11 give it a red thumbs-down.

Of Wall Street recommendations tracked by S&P Capital IQ, the average opinion on Arch Coal is hold, with an average price target of $16.55.

Are you missing a major story in the energy space? Read about "One Stock to Own Before Nat Gas Act 2011 Becomes Law." Click here for instant access to this free report.