Query cache check

mysql> show status like 'qc%';
+-------------------------+----------+
| Variable_name | Value |
+-------------------------+----------+
| Qcache_free_blocks | 3051 |
| Qcache_free_memory | 10365720 |
| Qcache_hits | 1650400 |
| Qcache_inserts | 757805 |
| Qcache_lowmem_prunes | 348499 |
| Qcache_not_cached | 9146 |
| Qcache_queries_in_cache | 10180 |
| Qcache_total_blocks | 24809 |
+-------------------------+----------+
8 rows in set (0.00 sec)

A couple important numbers from these values:
free space / free mem blocks = average free block size (in bytes)
10365720 / 3051 = 3398
used space / num queries in cache = average result size (in bytes)
(32 * 1024 * 1024 – 10365720) / 10180 = 2278

Source