# What is the maximum number of qubits that can be simulated by Qiskit using any method?

I'm looking to write an algorithm (potentially) using Qiskit, and am trying to find out what the maximum number of Qubits is that Qiskit can support with various simulation methods.

From reading other answers on here, and using Qiskit a bit, I have found that the Qasm simulator has a maximum of 30(?), but that Qiskit supports also using a GPU.

I assume the number of qubits a GPU can simulate depends on the GPU in question, but I am wondering if anyone knows how to find out what that number would be for a given GPU?

In addition, are there any other methods using Qiskit or otherwise wherein you can simulate a quantum computer running a complex algorithm, for example, one which requires several real numbers (including decimals) as variables? Not looking for specifics necessarily - any pointers will do, but specifics are very welcome!

Thanks in advance, and apologies if this is a silly question or I've missed something.

• You can use backend.configuration().n_qubits. This should return the number of qubits whether the backend is local simulator, cloud simulator, or quantum processor. Jun 30 at 18:13