Alliant Energy (NYSE: LNT) reported earnings on May 3. Here are the numbers you need to know.

The 10-second takeaway
 For the quarter ended March 31 (Q1), Alliant Energy beat expectations on revenues and beat expectations on earnings per share.

Compared to the prior-year quarter, revenue grew. Non-GAAP earnings per share grew significantly. GAAP earnings per share grew significantly.

Margins expanded across the board.

Revenue details
 Alliant Energy logged revenue of $859.6 million. The three analysts polled by S&P Capital IQ expected to see net sales of $765.4 million on the same basis. GAAP reported sales were 12% higher than the prior-year quarter's $765.7 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 $0.72. The eight earnings estimates compiled by S&P Capital IQ predicted $0.61 per share. Non-GAAP EPS of $0.72 for Q1 were 44% higher than the prior-year quarter's $0.50 per share. (The prior-year quarter included -$0.04 per share in earnings from discontinued operations.) GAAP EPS of $0.63 for Q1 were 97% higher than the prior-year quarter's $0.32 per share. (The prior-year quarter included -$0.04 per share in earnings from discontinued operations.)

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 27.9%, 130 basis points better than the prior-year quarter. Operating margin was 14.0%, 150 basis points better than the prior-year quarter. Net margin was 9.3%, 470 basis points better than the prior-year quarter. (Margins calculated in GAAP terms.)

Looking ahead
 Next quarter's average estimate for revenue is $643.2 million. On the bottom line, the average EPS estimate is $0.52.

Next year's average estimate for revenue is $3.24 billion. The average EPS estimate is $3.13.

Investor sentiment
 The stock has a three-star rating (out of five) at Motley Fool CAPS, with 85 members out of 99 rating the stock outperform, and 14 members rating it underperform. Among 33 CAPS All-Star picks (recommendations by the highest-ranked CAPS members), 28 give Alliant Energy a green thumbs-up, and five give it a red thumbs-down.

Of Wall Street recommendations tracked by S&P Capital IQ, the average opinion on Alliant Energy is outperform, with an average price target of $50.00.

Looking for alternatives to Alliant Energy? It takes more than great companies to build a fortune for the future. Learn the basic financial habits of millionaires next door and get focused stock ideas in our free report, "3 Stocks That Will Help You Retire Rich." Click here for instant access to this free report.