Just to further expand information already provided, this is very much an "it depends" answer.
Understand, on switches, generally, specially dedicated hardware is used for the data plane (which doesn't consume CPU, beyond setting it up), while the CPU is used mainly for the control plane.
I.e. a switch at even 100% may forward ordinary data traffic w/o any adverse effect to that data traffic. However, control plane functions (including any process switched packets [generally a bad thing on a switch]) might be very much impacted by high CPU usage. (The reason the latter is "might" is because, generally, control plane functions are prioritized. I.e. a "background" or low priority CPU function, even if it pushes the CPU to 100%, often has little impact to the overall control plane functioning because higher priority control plane functions will preempt it. However, the converse is bad, a high priority, very busy control plane function might "starve" lower priority control plane functions for their CPU needs.)
The noted Cisco recommendation, in the other posted replies, notes using 50% (average usage) as a metric. I.e. below 50%, likely you have no issues (not 100% true because there could be short transient CPU spikes). Above 50%, it's probably worthwhile to identify the cause and determine if you have an issue that might need mitigation. (Again, it's possible a "high" CPU usage average, in your situation, isn't a problem.)
