Yes - it will provide you with some degree of added protection.
Governments in the United States and the United Kingdom are encouraging fabric face masks as a way to protect others from the wearer’s respiratory emissions. This is important - and if everyone wore a mask, the risk of acquiring an infection in public would drop.
However, many people understandably want to know if the fabric face mask they wear will protect themselves. No study has shown a fabric face mask that, when worn, provides the same degree of protection as an N95 mask. However, fabric face coverings do indeed protect the wearer in a variety of ways!
Firstly, the fabric mask will filter some percentage of particles from the air. Our studies found fabric masks blocked, on average, upwards of 40% of particles from the air. This reduces the number of potentially harmful particles you are inhaling. For example, pretend a breath of air contains 100 particles (actual particle numbers in air samples very widely). Most of those 100 particles in this hypothetical sample are dust, pollen, and so on. However, 1 of those particles is something dangerous - like the novel coronavirus. If you did not have a mask, you would breathe in the virus. With a fabric face mask, there is a 40%+ chance that the harmful particle will not be inhaled.
Even if you do inhale pathogenic particles, it may be that you will inhale fewer of them. While it is only theory at this point, many doctors believe that the amount of virus or pathogen you receive impacts whether you get sick and, if you do get sick, how quickly and severely you get sick. For example, if you only inhale two virus particles, there is a good chance they will get stuck in your mucus and safety expelled - or perhaps they will get swallowed and digested into your stomach. Viruses must reach certain tissue types to get you sick - and the greater number of viruses you inhale, the greater the chance one or more will find their way to a susceptible tissue.
Another way fabric face masks protect the wearer is by limiting the amount of hand-to-face contact the wearer engages in. They can also serve as a reminder to others and to yourself to social distance.