Store and Forward Packet Latency Calculator
Estimate first and final packet arrival over equal-rate store-and-forward links, including packet overhead and per-hop propagation.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Serialize the complete packet on every link for first arrival. Equal-rate links pipeline subsequent packets one packet-serialization time apart.
tx=8(payload+overhead)/rate; first=hops(tx+propagation); final=first+(count−1)tx
Worked example
1000 payload bytes and 40 overhead bytes on a 100 Mbit/s link take 83.2 µs to serialize. Three links with 1 ms propagation each deliver ten packets in 3.9984 ms.
Assumptions and input details
All packets have the entered full payload size and every link has the same rate and propagation. Overhead is user supplied and must include every serialized byte you want counted. Store-and-forward routers with no queue, processing, loss, retransmissions, acknowledgments or startup congestion. This is a one-way packet pipeline, distinct from an RTT/receive-window throughput bound.
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
One byte is eight bits. Decimal prefixes (k, M, G, T, P, E) use powers of 1000. Binary prefixes (Ki, Mi, Gi, Ti, Pi, Ei) use powers of 1024. Transfer rates are per second.
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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