There's a lot of controversy surrounding the accuracy of the earnings calculator as it provides an estimate based on only 2 factors (Location & Industry). These two factors are very broad and have tons of sub-factors. Let's take a look:
1. Location - Here are 4 main categories combining multiple countries in each. Some of the important sub-factors are if your website is country specific (.co.uk / .co.za / .co.au / etc.) or international (.com / .net / .shop / etc.). If your website is intended for an international audience you will be able to have a much broader reach, but you also have much higher competition.
For your website to be successful in the online realm, you need to outrank the millions of other websites. There are only two ways to achieve this goal with a fairly new website.
The first method to increase traffic is by making use of Pay Per Click (PPC) ads where you advertise your business via a service such as Google Ads - effectively advertising your own website in ad units such as the ones above. If your goal is to cost efficiently monetize your website - PPC might not be your first choice.
The second method to get more website traffic is by making use of Search Engine Optimization (SEO). This is a cost effective, long term solution that will get your website ranking higher for specific search terms / keywords on a semi-permanent basis. SEO essentially increases your website's trust and authority. SEO can also drive clients directly to your website by placing links to your website pages on Private Blog Networks, Major Blog Networks, news sites, major social media platforms and more.
2. Industry - Each industry has a different amount of interest and competition, for example if your industry is 'Internet & Telecom' your estimated revenue is about double that of the 'Reference' industry. This is due to more Internet & telecom companies placing PPC ads than reference companies (such as directories).