11-point font is not too small for a resume. 10.5 font is the smallest size you can use on a resume that is still readable. Try a 10.5-point font if you have a lot of relevant experience, achievements, skills, and certifications to put on your resume and need to keep it to one or two pages.
Be aware that some fonts look smaller than others. These fonts need to be bigger in order to be easily read by a hiring manager:
- Gill Sans