A 320 GRE score sits at roughly the 88th percentile — comfortably in the “exceptional” range by most standards. Whether it's “good enough” depends entirely on what you're applying to, so here's a specific breakdown.
A 320 is well above the median for the large majority of Master's programs, including most professional and terminal Master's degrees. At this level, the GRE is very unlikely to be a limiting factor in your application — other components will carry more weight in differentiating you from other strong applicants.
For most PhD programs, a 320 is at or above the median. The exception is highly quantitative fields — certain economics, engineering, or computer science PhD programs may have applicant pools where the Quant median alone approaches 165–167, meaning your Quant sub-score specifically matters more than the combined 320.
A 320 split as 165V/155Q reads very differently than 155V/165Q to a quantitative program — even though the total is identical. If you're at 320 and applying to a quant-heavy field, check whether your Quant score specifically meets that program's typical range, not just your combined score.
Above 320, additional points have rapidly diminishing returns for most programs — the jump from 320 to 325 rarely changes an admissions outcome the way the jump from 300 to 310 might. Unless a specific program's data suggests otherwise, a 320 is usually a good stopping point to redirect your energy toward other parts of the application.