Which share price should I use to calculate EPS, P/E and PEG ratios for 2024 and 2025: historical prices or the current 2026 price?

Use historical share prices if you want to compare valuations for 2024 and 2025. Use the current 2026 price if you want to assess the shares at today’s price. But EPS does not use share price at all.

The difference is between “What did the business earn?” and “What were investors paying for those earnings?”

Imagine Mama Ngozi’s tomato business has been divided into shares. The profit belonging to each share comes from the business accounts. The price someone offers to buy a share is a separate matter. That price can change without changing the profit the business already earned.

Let us apply that to your three calculations.

EPS means earnings per share. It tells you how much of the company’s profit belongs to each ordinary share.

Basic EPS = Profit attributable to ordinary shareholders ÷ Weighted average number of ordinary shares during the year.

“Weighted average” simply means allowing for how long shares were in issue during the year, rather than automatically using the number at year-end.

For 2024 EPS, use the company’s 2024 figures. For 2025 EPS, use its 2025 figures. Neither calculation needs a share price.

The easiest starting point is the EPS already reported in the audited annual report. Check whether it is stated in naira or kobo. An EPS of 200 kobo is ₦2, not ₦200.

P/E means price-to-earnings ratio. It compares the price of one share with the earnings belonging to one share.

P/E = Share price ÷ EPS.

Suppose these are fictional figures:

At the end of 2024, the share price was ₦20 and full-year EPS was ₦2. The P/E calculated using those figures is 10.

At the end of 2025, the share price was ₦30 and full-year EPS was ₦2.50. The P/E is 12.

Now suppose the price in 2026 is ₦40. Dividing ₦40 by the 2025 EPS of ₦2.50 gives a P/E of 16.

That last calculation is valid, but label it correctly: “Current P/E using 2025 full-year earnings.” It is not the historical 2025 P/E.

For a simple year-by-year comparison, you can use the closing price on the last trading day of each company’s financial year, divided by that year’s EPS. Use the same method throughout.

But there is one important catch: full-year results are usually published after the year ends. So this is a comparison made with hindsight. If you want to know what an investor could actually have calculated on a particular date, use only earnings information already published by that date.

PEG takes the P/E and compares it with earnings growth.

PEG = P/E ÷ EPS growth rate expressed as a percentage number.

Using the fictional figures above, EPS rose from ₦2 to ₦2.50. That is 25% growth.

Using the 2025 P/E of 12:

PEG = 12 ÷ 25 = 0.48.

Use 25, not 0.25, in that calculation. Label this a PEG based on historical one-year growth. Many PEG calculations instead use expected future growth, so check the method before comparing figures. A low PEG alone does not prove a share is cheap, especially if profit jumped because of a one-off gain. PEG is generally not useful when earnings growth is zero or negative.

To get the historical prices, check NGX historical market reports or request dated closing prices from your stockbroker. Get EPS from the company’s audited reports on its investor relations page or NGX filings.

Also check for share splits or bonus issues. Prices and EPS must reflect the same share basis. Do not automatically use a data provider’s “adjusted close”, because it may also include dividend adjustments.

The simple rule is: EPS comes from the accounts. P/E adds the price for your chosen date. PEG adds a clearly stated earnings-growth measure. Always write down the dates and method beside your calculation.