Just because you can see your desktop site on a mobile phone doesn’t mean it’s mobile-friendly. Mobile sites are designed for the small screen, with the needs of mobile users in mind. A mobile-friendly site can help your business connect with customers and drive conversions.
(source: Google)

Here are some tips from Google to help you decide if your website is mobile friendly (according to Google standards):

1. Speed: Your mobile site must load in less than 5 seconds (the faster the better). Close to 50% of visitors will wait just 5 seconds or less before giving up on a site (source: Compuware, What Users Want from Mobile, 2011). Mobile consumers are usually short on time, squeezing in online tasks when they can. Prioritize your content with the mobile user in mind. Compress images for faster loading.

2. Easy Navigation: Make it easy for your mobile customer to find what they need. Minimize scrolling, never have horizontal scrolling. Use seven links or fewer per page.

3. Be Thumb Friendly: Mobile surfers use their fingers to surf, especially their thumbs. Give all buttons breathing room to reduce accidental clicks.

4. Design For Visibility: A mobile-friendly site gets its message across without causing eyestrain. Content MUST fit onscreen and be read without pinching and zooming.

5. Accessibility: Ideally, your mobile site will work on all mobile devices and handset orientations. Do NOT ever use Flash — it does not work on any Apple product. At the least be sure to adapt your site for both vertical and horizontal orientations.

6. Make Things Easy for The User: Your customers are coming to your site with no keyboard or mouse, so be sure to make things easy for them to contact you. Reduce the number of steps needed to get in touch with you. Keep forms short and use the least amount of fields possible.

7. Show You Are Local: Consumers are looking for local info on their phones all the time. So have your address or store locator easily accessible. Include maps and even directions when possible.

8. Make It Seamless: Maintain the key features of your site across all platforms as much as possible. Display the same information for products/services everywhere.

9. Use Mobile ReDirects: A mobile site redirect is code which is placed on your main site which can automatically tell if visitors are using a mobile device and send them to the mobile-friendly version of your site, giving customers the best version of your site for their needs. Make sure to give users a choice to go back to the desktop site from your mobile, and to your mobile from your desktop version.

10. Listen To Your Visitors: Continue to tweak your site based on your users needs. Make testing and optimization an ongoing process. Keep up on the latest trends to continually improve your site.

Bottom line you need to ensure an optimal experience for your mobile users — providing the content they’re most likely to want upfront.