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Portfolio Beta Calculator.

Calculate portfolio beta from asset weights and betas.

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Set your values

Results update as you type.

Portfolio beta: 1.5

Portfolio beta

1.5000

FAQs

How does the portfolio beta calculator work?

Enter the requested values to receive a deterministic result. No live market, tax, or jurisdiction data is inferred.

Cite this calculator

Canonical URL: https://mathify.one/fr/finance/portfolio-beta

Cite as: Mathify. (2026). Calculatrice: Portfolio Beta. https://mathify.one/fr/finance/portfolio-beta

Use Cases

Assess portfolio risk

Investors use beta to understand how much risk a portfolio carries relative to the market. A higher beta suggests higher volatility and potential for larger swings.

Example: If your portfolio has a beta of 1.5, it is expected to move 1.5 times the market's movement.

Compare investment options

Financial analysts compare betas of different portfolios or stocks to decide which aligns with their risk tolerance and investment strategy.

Example: Choosing between two mutual funds: one with beta 0.8 (conservative) and another with beta 1.2 (aggressive).

Frequently Asked Questions

What is portfolio beta?
Portfolio beta measures the sensitivity of a portfolio's returns to market movements. A beta of 1 means the portfolio moves with the market, >1 indicates higher volatility, and <1 indicates lower volatility.
How is beta calculated using this calculator?
Beta is calculated by dividing the covariance of portfolio and market returns by the variance of market returns. Simply input the covariance and market variance values, and the calculator will compute the beta.
What do the inputs mean?
Portfolio/market covariance measures how portfolio returns move with market returns. Market return variance measures the dispersion of market returns. Both are typically calculated from historical return data.

Tips & Common Mistakes

Tips

  • Ensure your covariance and variance are calculated over the same time period and using the same frequency of returns (e.g., daily, monthly) for accurate beta.
  • Beta is based on historical data; past performance does not guarantee future results. Use it as one of several risk metrics.
  • If you have return data, you can compute covariance and variance using spreadsheet functions like COVARIANCE.P and VAR.P.
  • For a diversified portfolio, beta can be lower than the average beta of individual stocks due to diversification benefits.

Common Mistakes to Avoid

  • Using covariance and variance from different time periods or frequencies, leading to an inaccurate beta.
  • Confusing covariance with correlation. Beta requires covariance, not correlation, though correlation can be used to derive beta if standard deviations are known.
  • Assuming beta is constant over time; it can change as market conditions and portfolio composition change.

Last updated: August 13, 2026