THE NUMBERS, EXPLAINED
How to use this calculator.
A steady-state average model: one transaction holds one connection for the measured time. It estimates offered load, not latency percentiles or safe production sizing. Values above 100% existing utilization indicate overload under these assumptions.
Start with your inputs
Enter arrival rate (transactions/s), measured connection-held time (ms), existing connections, target utilization (%). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Arrival rate (transactions/s) | 100 |
| Measured connection-held time (ms) | 50 |
| Existing connections | 10 |
| Target utilization (%) | 70 |
A worked example
With the example inputs above, offered concurrent transactions is 5. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Offered concurrent transactions | 5 |
| Ideal existing capacity (transactions/s) | 200 |
| Existing offered utilization (%) | 50 |
| Connections at target utilization | 8 |
How this is calculated
Offered concurrent transactions
Arrival rate × held time in seconds.
Ideal existing capacity (transactions/s)
Connections ÷ held time in seconds.
Existing offered utilization (%)
Offered concurrency ÷ existing connections × 100.
Connections at target utilization
Round up offered concurrency ÷ target utilization fraction.
Symbols and units
- a
- Arrival rate (transactions/s)
- b
- Measured connection-held time (ms)
- c
- Existing connections
- d
- Target utilization (%)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions and limits
A steady-state average model: one transaction holds one connection for the measured time. It estimates offered load, not latency percentiles or safe production sizing. Values above 100% existing utilization indicate overload under these assumptions.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Offered concurrent transactions; Ideal existing capacity (transactions/s); Existing offered utilization (%); Connections at target utilization. The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: A steady-state average model: one transaction holds one connection for the measured time. It estimates offered load, not latency percentiles or safe production sizing. Values above 100% existing utilization indicate overload under these assumptions.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
OpenStax: percentages and proportions ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
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