The cache miss ratio is the complement of the cache hit ratio. If h represents the hit ratio, then the miss ratio, which is the proportion of cache accesses that result in a miss, is calculated as 1 − h.
Suppose the hit ratio h is 0.75. This means 75% of the cache accesses result in a hit.
To find the Miss ratio
Miss Ratio = 1-h
Miss Ratio = 1 – 0.75
Miss Ratio = 0.25
So, 25% of the cache accesses result in a miss.