Jitter Calculator
Calculate network jitter (latency variation) from a series of latency measurements.
Inputs
Comma-separated latency values in ms, e.g. 45, 48, 46, 52, 44
Average Jitter
4.333ms
RFC 3550 Smoothed Jitter
1.399ms
Max Jitter (Single Step)
8.000ms
Mean Latency
47.286ms
Step by step
Values used
Latency Measurements = 45, 48, 46, 52, 44, 49, 47
Simple average jitter
jitter = average(|latency[i] − latency[i-1]|) for consecutive samples
RFC 3550 smoothed jitter
J = J + (|D| − J) / 16
Average Jitter
= 4.333 ms
RFC 3550 Smoothed Jitter
= 1.399 ms
Max Jitter (Single Step)
= 8.000 ms
Mean Latency
= 47.286 ms
How it works
Jitter is the variation in packet delay over time, not the delay itself. The simplest measure is the average absolute difference between consecutive latency samples. RTP-based systems (VoIP, video) commonly use the RFC 3550 exponentially-smoothed estimator, J = J + (|D| − J)/16, where D is the difference between consecutive transit times, which reacts gradually to give a stable running estimate that's less sensitive to single outliers.
Formulas
Simple average jitter
jitter = average(|latency[i] − latency[i-1]|) for consecutive samples
- L_i
- The i-th latency measurement
- n
- Number of measurements
RFC 3550 smoothed jitter
J = J + (|D| − J) / 16
- D
- Difference in transit time between two consecutive packets
Frequently Asked Questions
How is jitter different from latency?
Latency is how long a single packet takes to arrive. Jitter is how much that delay varies from packet to packet. A link can have high latency but low jitter (consistently slow) or low latency but high jitter (usually fast, occasionally spikes).
Why does jitter matter for VoIP and video calls?
Real-time audio/video is played out at a fixed rate. If packet delay varies too much, the playout buffer either runs dry (causing gaps/glitches) or overflows, so high jitter causes choppy audio and video even without any packet loss.
What jitter value is considered good for VoIP?
Under about 30ms of jitter is generally considered good for VoIP; above that, call quality noticeably degrades unless the jitter buffer is enlarged, which in turn adds more latency.
Why use the RFC 3550 smoothed formula instead of a simple average?
The RFC 3550 estimator weights recent samples more heavily and updates continuously, so it responds to real trends in network conditions without being thrown off by a single one-off delay spike the way a simple average of all samples can be.