How to use this calculator
- Enter aligned market returns (%), aligned asset returns (%).
- Choose a display currency, then select Calculate. Results also update after a brief pause while you edit.
- Read the result with the assumptions below. Export details or save a second scenario to compare your choices.
Formula and method
Assumptions and limitations
Use your own matching-period observations. These descriptive calculations are not forecasts, investment advice or a national dataset. Lists accept up to 100 comma-separated numbers; do not enter thousands separators. Aligned equal periods required; a constant market series is rejected.
Worked example
For the sample inputs shown above, historical portfolio beta produces a first result of approximately 2. The assumptions below explain what this result represents.
What the result means
Estimate historical sensitivity to the market series you supply.
Common questions
How is the calculation performed?
Beta = sample covariance(asset,market) / sample variance(market).
What does the model leave out?
Use your own matching-period observations. These descriptive calculations are not forecasts, investment advice or a national dataset. Lists accept up to 100 comma-separated numbers; do not enter thousands separators. Aligned equal periods required; a constant market series is rejected.
Methodology and transparency
Calculation specification reviewed on 2026-10-14. Mathematical implementation is tested against independent reference fixtures. This does not imply review by a licensed financial professional. Read the testing and precision policy.
Background reference: www.itl.nist.gov — financial method. FinanceMath implements its own calculator.