Basic earnings refer to the portion of a company's net profit or loss that is attributable to each outstanding ordinary share of its stock. Basic earnings are calculated by dividing the company's net profit or loss attributable to ordinary shareholders by the weighted average number of ordinary shares outstanding during the period.

Under IAS 33, basic earnings per share (EPS) are calculated using the following formula:

Basic EPS = (Net profit or loss attributable to ordinary shareholders) / (Weighted average number of ordinary shares outstanding during the period)

Net profit or loss attributable to ordinary shareholders is the profit or loss that is available for distribution to holders of ordinary shares after deducting any dividends payable on preferred shares or other non-equity instruments.

The weighted average number of ordinary shares outstanding during the period is calculated by multiplying the number of shares outstanding at the beginning of the period by the time-weighted average of the number of shares outstanding during the period.

Basic EPS is an important metric that investors use to evaluate a company's financial performance, as it provides a measure of the profitability of each share of a company's stock.

Here is an example of how to calculate basic earnings per share (EPS) under IAS 33:

Assume that a company has a net profit of $1,000,000 for the year ended December 31, 2022. The company has 1,000,000 ordinary shares outstanding for the entire year.

To calculate the basic EPS, we need to determine the weighted average number of ordinary shares outstanding during the year. Let's assume that the company had 500,000 ordinary shares outstanding for the first six months of the year and 1,500,000 ordinary shares outstanding for the second six months of the year due to a stock issuance.

Weighted average number of ordinary shares outstanding = [(500,000 x 6/12) + (1,500,000 x 6/12)] = 1,000,000

Using the formula for basic EPS, we can calculate:

Basic EPS = Net profit / Weighted average number of ordinary shares outstanding

= $1,000,000 / 1,000,000

= $1.00 per share

Therefore, the basic EPS for the year ended December 31, 2022, is $1.00 per share. This means that for every share of the company's stock outstanding during the year, the company earned a net profit of $1.00. Investors can use this information to evaluate the company's financial performance and make informed investment decisions.