# Price to earnings ratio

(PER).

The ratio of the equity value of a company to its accounting earnings (profit after tax).

The PER (or PE ratio) can be calculated either on a per-share basis or on the total equity value and total earnings, giving identical results.

Per share:

PE ratio = Current share price ÷ Earnings per share.

On total values:

PE ratio = Total equity value ÷ Total earnings.

**Example 1**

Company A's total equity value is $630m and its relevant earnings are $63m,

the PE ratio = $630m / $63m

= 10.

The Price to earnings ratio reflects the market's perception of the risk and the future growth prospects of the company.

A higher PE ratio generally indicates that the market perceives:

- better growth
- lower risk
- or both

Lower PE ratios suggest lower growth (or indeed decline), higher risk, or both

PE ratios can also be used as a very simple estimation or comparison model, for corporate valuation.

**Example 2**

In another case, say comparable PE ratios for an unlisted Company B are 12, and Company B's relevant earnings are $10m.

The total value of Company B's equity can be estimated on this basis as:

12 x $10m

= $120m.

Very simplistically, shares trading on low PE ratios might be perceived as relatively cheap. Similarly, shares trading on higher PE ratios would be seen as relatively expensive.

A better use of PE ratios is as a sense-check of the results and insights from other valuation methods.

Sometimes written as *P/E ratio*.

*Also known as price earnings ratio.*