The number of qubits you can run depends on many factors. Here are some important factors:

The compute resources you have. Running circuits on a laptop is more limiting than running them in a server or a supercomputer.

The depth of your circuit. If you have a very shallow circuit you may be able to run larger circuits in some cases.

The tools you use. If you’re using circuit optimization/compilation techniques like circuit cutting you might get to run circuits with more qubits.

If you’re running a circuit of moderate depth on a laptop without using circuit cutting or similar techniques, here’s a quick reference for how many qubits you could run using different simulators:

default.qubit and lightning.qubit: up to 26 qubits

lightning.gpu and lightning.kokkos (using GPUs): up to 29 qubits.
If you optimize using MPI you can get maybe 3 extra qubits.

default.mixed: up to 16 qubits

Remember that aside from the device you will need to choose an interface, which is autograd/numpy for default but you can also choose Torch or Tensorflow.

You can dig deeper into choosing a device in this blog post.

I hope this helps you! Let us know how many qubits you get to run with each device.