LEARNING TOOLS · VERSION 1.0

Put the numbers in context.

Explore two simple models. Change the inputs and copy a result with the assumptions needed to interpret it.

Statevector memory

How much memory does one dense quantum state array require on a classical computer?

Number of qubitsWhole number from 0 to 60. Double precision, 16 bytes per complex value.16 GiB17,179,869,184 bytes for the state array.

The model

Memory = 16 × 2ⁿ bytes

Each extra qubit doubles this array. At 30 qubits the model gives 16 GiB. At 31 it gives 32 GiB. A GiB is 1,073,741,824 bytes.

Real simulators need additional working memory. Other methods can use very different amounts. This does not estimate a quantum computer’s physical memory, speed or cost.

Model basis: Qiskit Aer documentation

Repeated independent trials

How many tries give a chosen chance of observing at least one success?

Success probability per trialFrom 0 to 1. For 1%, enter 0.01. Up to 15 significant digits; nonzero values must be at least 1e-300.Target probabilityFrom 0 to 1. For 95%, enter 0.95. Up to 15 significant digits; nonzero values must be at least 1e-300.299 trialsMinimum for the target under this model. Resulting probability: 95.04637% (approximately).

The model

P(at least one success) = 1 − (1 − p)ⁿ

With a 1% success probability, 299 independent tries reach a 95% target. With 298 tries the probability remains below 95%.

The probability must be known and unchanged between independent trials. Correlated errors or drift break those assumptions. This is not statistical confidence or an estimate of quantum advantage or error-correction resources.

Model basis: NIST binomial distribution

Continue with the explanation

Hybrid quantum computing: understand where a classical simulator or a quantum processor fits into a workflow.
Physical and logical qubits: understand why error correction needs a different resource model.

Inputs stay in this page. These calculations do not change your saved items or require an account. Model version 1.0.