Quantum Circuit Error Budget Calculator

Quantify how hardware infidelity accumulates across compiled quantum circuits by combining gate counts, ppm error rates, and measurement fidelity into a single success estimate.

Total single-qubit operations in the compiled circuit depth.
Average error probability per single-qubit gate in parts per million.
Number of entangling gates (CNOT, CZ, etc.) in the circuit.
Average error probability per two-qubit gate in parts per million.
Number of terminal qubit measurements or mid-circuit readouts. Defaults to the qubit count when blank.
Infidelity per measurement event. Defaults to 500 ppm when blank.

Analytical planning aid. Validate against hardware calibration data and noise-aware simulation before committing to production workloads.

Examples

  • 320 single-qubit gates at 45 ppm, 180 two-qubit gates at 210 ppm, 64 measurements at 500 ppm ⇒ Circuit success 86.06% with 0.21 expected failure events.
  • 200 single-qubit gates at 35 ppm, 90 two-qubit gates at 150 ppm, measurements left blank (defaults to 45) ⇒ Circuit success 91.67% and 0.12 expected failure events.

FAQ

Can I input error rates in percent?

Provide ppm values (parts per million). Multiply your percent value by 10,000 before entering it so 0.1% becomes 1,000 ppm.

How do I include reset operations?

Treat active resets as additional measurements and include them in the measurement count, paired with the appropriate ppm error rate for the hardware.

What if error mitigation is applied?

Recalculate effective error rates after mitigation and input those values. The calculator assumes post-mitigation probabilities supplied by tomography or benchmarking.

Additional Information

  • Result unit: probability expressed as percentages plus expected error-event count.
  • Measurement count defaults to half the two-qubit gate count when not provided, approximating qubits touched in typical ansatz circuits.
  • Error rates are interpreted as independent Bernoulli events; correlated crosstalk or leakage requires bespoke modelling.

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