"在一般水准以上" can be translated into English as "above average" or "above the norm".
"Above average" is a commonly used phrase that directly conveys the idea of being better than the typical or standard level.
"Above the norm" also works, though it's slightly less common in everyday conversation and might be more formal or technical in some contexts. It emphasizes exceeding the established or expected standard.
For most general contexts, "above average" would be the most natural and widely understood choice.