Packet loss rate calculator
The Packet loss rate calculator computes packet loss rate from the relation loss = lost / sent x 100. It takes 2 inputs (packets lost, packets sent) and returns the packet loss rate in %. These calculators are for network and systems administrators, software and hardware engineers, and computing students, turning a stated value, address, string or configuration into the exact figure, code or encoding that the rule behind it produces, without working it through by hand. Enter your values below and the result updates instantly, and you can share a permalink that pre-fills the exact calculation. Check the base, unit and width of each input before entering it: hexadecimal against decimal, bits against bytes, binary against decimal prefixes, and 0-based against 1-based positions are the usual sources of a wrong answer here, and a result that is out by a neat factor is far more often one of those than an arithmetic slip. For example, with packets lost = 10, packets sent = 100, the packet loss rate works out to 10 %, and the worked example further down the page shows every step so you can follow the arithmetic and reproduce it by hand. This is a standard formula rather than a jurisdiction-specific rule, so it does not depend on an external rate or schedule, and the figure above each result carries the date it was last verified. The result follows the definition and the exact values you supply, so it can differ from what a live system reports: reserved and unusable values, protocol and filesystem overhead, the width and precision of the data type actually in use, and the conventions a particular language, device or display applies all sit outside the calculation, so confirm the figure against the environment it will be used in.
With Packets lost = 10, Packets sent = 100, the result is 10 %.
Applies to: any numeric inputs. Method: a standard formula, not a jurisdiction-specific rule. How we document and test our methods, checked 2026-06-22.
The formula
loss = lost / sent x 100
Worked example
With Packets lost = 10, Packets sent = 100:
- loss = lost / sent x 100
- Packet loss rate = 10 %
This worked example is one of the automated golden-value tests this calculator must pass before it can publish.
What this assumes
- Inputs are real numbers in the units shown.
- The result is the exact value of loss = lost / sent x 100; general information, not professional advice.
Frequently asked questions
What formula does this use?
loss = lost / sent x 100. This is a standard formula rather than a jurisdiction-specific rule.
Does the result ever change over time?
No. This is a pure formula with no external rate, so the same inputs always give the same result.
Official sources and verification
- Method: a standard formula rather than a jurisdiction-specific rule; how we document and test our methods, checked 2026-06-22.
Reviewed by the CalculatorHub team, edited by James Graham, 2026-06-22. See our methodology. General information, not professional advice.