How to use this calculator
- Enter or choose packets sent.
- Enter or choose packets received.
- The packet loss updates as you type. Use Copy result or Share to keep it.
Method
Loss % = (Sent − Received) ÷ Sent × 100; Delivered % = Received ÷ Sent × 100
- Sent
- packets transmitted
- Received
- packets that arrived (duplicates removed)
Worked example
- Lost = 1,000 − 987 = 13 packets.
- Loss = 13 ÷ 1,000 × 100 = 1.3%.
13 of 1,000 packets were lost, a packet loss of 1.3%.
What the result means
Even small, sustained loss cuts TCP throughput and causes glitches in voice and video. Measure over enough packets: with only 4 pings, one lost reply already shows 25%.
Assumptions and limits
- Counts come from the same interval at both ends.
- Routers often rate-limit ping replies, so ICMP loss at an intermediate hop does not always mean real traffic is being dropped.
Questions
Why can received exceed sent?
Duplicated or retransmitted packets. Remove duplicates before calculating; this calculator rejects received above sent.
How many packets should I test with?
Hundreds or more. Each lost packet in a 100-packet test moves the result by a whole percentage point.