EC2 Network Throughput Calculator

MB/s = Gbps × 125 × efficiency; transfer time = burst window + remaining bytes ÷ baseline rate once credits are spent. Smaller EC2 instance types advertise an 'up to' network figure funded by a credit bucket and a much lower sustained baseline. Any transfer long enough to drain the bucket therefore runs in two phases, and the average throughput lands between the two rates — often far closer to the baseline. The efficiency factor accounts for headers, TLS and acknowledgements, which never let you reach the raw line rate.

Sizing a migration or backup window off the 'up to' number is the single most common EC2 network planning error, and it can be an order of magnitude optimistic on a small instance.

This calculator takes 5 inputs: Burst network bandwidth, Sustained baseline bandwidth, Burst duration available, Data to transfer, Protocol and encryption efficiency. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.

Generally the larger sizes: types at 4xlarge and above (and anything advertising a plain Gbps figure without 'up to') hold their rated bandwidth continuously. If a transfer window is critical, size up or split the transfer across instances.