Performance calculators
10 free calculators, no login — type a number, see what it means.
Capacity sizing
Size a service for 1,200 requests a second with room to absorb spikes.
Tail latency
A page makes 20 backend calls. How often does at least one hit the p99?
Cache benefit
Estimate what raising your cache hit ratio does to average response time.
Transfer time
How long will a migration or backup take over the available link?
Apdex score
Turn response times into a single satisfaction score from 0 to 1.
Latency and revenue
Estimate what extra load time costs a store or checkout. Use your own measured sensitivity
Peak concurrency
Estimate how many users are online at the same moment from daily actives.
Shannon capacity
Compare a link’s real throughput with the theoretical maximum for its bandwidth and signal
Percentiles and stats
Paste response times, durations or any list of numbers to get the median, p95, p99 and spr
Data units
Convert between decimal (GB) and binary (GiB) sizes, bytes and bits.