DNS Query Rate Calculator
Turn user population into average and peak DNS query rates and the number of resolvers required.
About DNS Query Rate Calculator
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
Worked example
With the default values below, DNS Query Rate Calculator returns Peak Query Rate of 1,666.7. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Users or devicesminimum 1 users
- 10,000 users
- Queries per user per hourminimum 0.1 queries/h
- 200 queries/h
- Peak-to-average factoraccepts 1–20 ×
- 3 ×
- Resolver cache hit ratioaccepts 0–100 %
- 80 %
- Capacity per resolverminimum 1 queries/s
- 50,000 queries/s
Results
- 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
Step by step
- 1Values used
- 2DNS Query Rate
- 3Load reaching authoritative servers
- 4Peak Query Rate= 1,666.7 queries/s
- 5Average Query Rate= 555.6 queries/s
- 6Upstream / Authoritative Rate= 333.3 queries/s
- 7Resolvers Required (N+1)= 2
- 8Queries Per Day= 48,000,000
Assumptions and limits
- The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
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.