DNS Query Rate Calculator
Turn user population into average and peak DNS query rates and the number of resolvers required.
Inputs
Peak Query Rate
1,666.7queries/s
Average Query Rate
555.6queries/s
Upstream / Authoritative Rate
333.3queries/s
Resolvers Required (N+1)
2
Queries Per Day
48,000,000
Step by step
Values used
Users or devices = 10,000 users; Queries per user per hour = 200 queries/h; Peak-to-average factor = 3 ×; Resolver cache hit ratio = 80 %; Capacity per resolver = 50,000 queries/s
DNS Query Rate
average qps = users × queries per hour ÷ 3600; peak qps = average × peak factor.
Load reaching authoritative servers
upstream qps = peak qps × (1 − cache hit ratio)
Peak Query Rate
= 1,666.7 queries/s
Average Query Rate
= 555.6 queries/s
Upstream / Authoritative Rate
= 333.3 queries/s
Resolvers Required (N+1)
= 2
Queries Per Day
= 48,000,000
How it works
Average rate comes straight from population and per-user query volume; the peak factor accounts for login storms and morning ramp-up. Only the cache-miss fraction reaches upstream, and resolver count is sized on peak with one spare unit. DNS is on the critical path for every session, so it must be sized for the peak second rather than the daily average — a resolver that saturates during a login storm looks to users like a total outage.
Formulas
DNS Query Rate
average qps = users × queries per hour ÷ 3600; peak qps = average × peak factor.
- peak factor
- Ratio of busiest-second rate to the daily average
- queries per hour
- Per-user query volume including retries and negative lookups
Load reaching authoritative servers
upstream qps = peak qps × (1 − cache hit ratio)
- cache hit ratio
- Fraction of queries the resolver answers locally
Frequently Asked Questions
How is DNS Query Rate calculated?
average qps = users × queries per hour ÷ 3600; peak qps = average × peak factor. Average rate comes straight from population and per-user query volume; the peak factor accounts for login storms and morning ramp-up. Only the cache-miss fraction reaches upstream, and resolver count is sized on peak with one spare unit.
Why does DNS Query Rate matter?
DNS is on the critical path for every session, so it must be sized for the peak second rather than the daily average — a resolver that saturates during a login storm looks to users like a total outage.
What values do I need to enter?
This calculator takes 5 inputs: Users or devices, Queries per user per hour, Peak-to-average factor, Resolver cache hit ratio, Capacity per resolver. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.