Skip to main content

Data Migration Downtime Estimator

Estimate time and downtime for database migrations based on volume and bandwidth. Enter values for instant results with step-by-step formulas.

Share this calculator

Worked Examples

Example 1: Lift & Shift

Problem: 50TB, 10Gbps Link, Low Complexity

Solution: Wire speed ~11 hours. With overhead ~14 hours.

Result: ~14 Hours Transfer

Example 2: Complex ETL

Problem: 10TB, 1Gbps Link, High Complexity

Solution: Wire speed ~22 hours. With complex transformation (0.5 efficiency) ~44 hours.

Result: ~44 Hours Transfer

Frequently Asked Questions

What affects migration speed most?

Usually Disk I/O (Read/Write speed), not Network. A 10Gbps link is fast, but if your source database can only read at 200MB/s, the network will be underutilized.

What is a 'Big Bang' migration?

Moving everything at once and switching over instantly. It requires a longer downtime window but is simpler to orchestrate. High risk if it fails.

What is 'Phased' migration?

Moving data in chunks (e.g., by region or customer ID) or running parallel systems. Zero/Low downtime, but high complexity to keep data in sync.

How do I minimize cutover downtime?

Use CDC (Change Data Capture). Replicate data continuously in real-time. During cutover, you only need to wait for the replication lag (seconds/minutes) to catch up.

Does this include Snowball/Data Box?

No, Data Migration Downtime Estimator assumes network transfer. Physical devices (AWS Snowball) have a fixed shipping time (days) but immense bandwidth (Petabytes).

Is my data stored or sent to a server?

No. All calculations run entirely in your browser using JavaScript. No data you enter is ever transmitted to any server or stored anywhere. Your inputs remain completely private.