Check RabbitMQ queue size from client

If you want to do this in .NET, check which version of the client library you are using.

I'm using the 2.2.0 version and I had to use BasicGet(queue, noAck).
In this version of the library, QueueDeclare() only returns a string containing the queue name.

BasicGetResult result = channel.BasicGet("QueueName", false);
uint count = result != null ? result.MessageCount : 0;

I know from the 2.6.1 version, QueueDeclare() returns an object of type QueueDeclareOk.

QueueDeclareOk result = channel.QueueDeclare();
uint count = result.MessageCount;

Alternatively, you can call from the command line:

<InstallPathToRabbitMq>\sbin\rabbitmqctl.bat list_queues

And you see the following output:

Listing queues...
QueueName 1
...done.