Source: HomeServicesAmerica

Every year, I value Berkshire Hathaway (NYSE:BRK.B) (NYSE:BRK.A) using the "two-column" approach (if you're not familiar with this approach, don't worry, I'll explain it). About a year ago, I found it to be at least 20% undervalued at $107 per B-share. Fast-forward to 2014, and the B-shares have advanced 8% to $116. So I figured it was time to sharpen up my pencil and re-estimate the value.

My conclusion: It is just as undervalued, even at today's higher prices.

My valuation approach
Berkshire is a huge company and notoriously difficult to value. Fortunately, Warren Buffett provides a pretty good framework for evaluating the intrinsic value. He laid it all out in his 2010 letter to shareholders. Basically, the value of Berkshire Hathaway shares comes down to two quantitative factors:

  1. Investments per share.
  2. Operating earnings per share.

Read on to see my math and assumptions. You're free to use this two-column-approach methodology to create your own valuation.

1. Investments per share
As of the end of 2013, Berkshire held $129,253 per A-share in investments (or about $86 per B-share). That's an increase of 14% during the year. The portfolio of investments includes debt and stock in quite a few companies, but the "big four" are American Express, Coca-Cola, IBM, and Wells Fargo. Most of these investments are liquid with reliable market prices. Thus, I simply value the investment portfolio at $86 per B-share.

2. Operating earnings per share
During 2013, Berkshire's operating businesses generated $9,116 per A-share in pre-tax earnings (or $6.08 per B-Share). This represents 13% growth over the previous year. So what's $6.08 per B-share worth? The S&P 500 trades at 20 times after-tax earnings, or 13 times pre-tax earnings if you assume a 33% tax rate. Some might argue that since Berkshire's collection of businesses are higher-quality than the index, they deserve a premium. Some might also argue that the index is overpriced at the moment. I won't delve into that debate, which is highly subjective by nature. I'll just be conservative and assume Berkshire's operating businesses are worth at least 10 times pre-tax earnings, or $61 per B-share.

Foolish bottom line
If I sum up $86 per B-share in investments and $61 per B-share for the operating businesses, that gives me a grand total of $147 per B-share. With the stock trading at about $116 per B-share, it's more than 20% undervalued, even using a very conservative set of assumptions. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.