Network Delay Calculator
Break down total network delay into propagation, transmission, processing and queuing delay.
About Network Delay Calculator
Total network delay is the sum of four components: propagation delay (time for a signal to travel the physical distance), transmission delay (time to push all bits onto the link), processing delay (time for routers to examine and forward the packet), and queuing delay (time spent waiting in router buffers).
Formula
Total delay
total = propagation + transmission + processing + queuing
- d_prop
- distance / propagation_speed
- d_trans
- packet_size / link_rate
Worked example
With the default values below, Network Delay Calculator returns Total End-to-End Delay of 7.6200. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Distanceminimum 0 km
- 1,000 km
- Propagation Speedminimum 1 km/s
- 200,000 km/s
- Packet Sizeminimum 1 bits
- 12,000 bits
- Link Rateminimum 0.001 Mbps
- 100 Mbps
- Processing Delayminimum 0 ms
- 0.5 ms
- Queuing Delayminimum 0 ms
- 2 ms
Results
- Total End-to-End Delay
- 7.6200 ms
- Propagation Delay
- 5.0000 ms
- Transmission Delay
- 0.1200 ms
- Processing Delay
- 0.5000 ms
- Queuing Delay
- 2.0000 ms
Step by step
- 1Propagation delay= 5 ms
- 2Transmission delay= 0.12 ms
- 3Processing delay= 0.5 ms
- 4Queuing delay= 2 ms
- 5Total delay= 7.62 ms
Assumptions and limits
- The result is derived only from the 6 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 4 decimal places, 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
Which delay component dominates?
On long-distance links (WAN/internet), propagation delay typically dominates. On short-distance, low-bandwidth links, transmission delay may dominate. Queuing delay dominates under congestion regardless of distance.
Why is queuing delay variable?
Queuing delay depends on the current traffic load — when a router's output buffer is empty, queuing delay is zero; when many packets compete for the same output link, each waits behind those ahead of it, making queuing delay highly variable and load-dependent.