The trimmer diameter can be categorized into three types that determine which diameter is best for what kind of jobs.
0.065" to 0.080" is the ideal range for cutting grass and soft weeds. 0.080" to 0.110" is considered to be the best choice for moderate jobs, or you can say cutting grass and thick weeds.
More than 0.110" is perfect for large scale jobs where you need to cut grass and heavy weeds for an extended area.