Speedy Calculator

Portfolio Beta Calculator

Finance Updated October 25, 2026

Quick answer

The portfolio beta calculator works out the beta of a portfolio as the value-weighted average of the betas of its holdings, showing how much the whole portfolio is expected to move with the market.

Portfolio beta
—
Total portfolio value
$ —
Risk compared with the market
—

Combining high- and low-beta stocks lets you set the overall market risk of a portfolio. A portfolio beta of 0.8 would be expected to fall about 8% when the market falls 10%.

How to use the Portfolio Beta Calculator

  1. Betas of each holding
  2. Value of each holding

Results update as you type, and every field accepts the units shown in its menu.

How it works

Enter the betas of your holdings and their values (or weights), in the same order.

Tips

  • Take figures from the same financial statements and the same fiscal year.
  • Compare ratios with companies in the same industry, not across industries.
  • Use several valuation measures together; no single ratio tells the whole story.
  • Market prices change every second – refresh the share price before you rely on a result.

Common mistakes to avoid

  • Mixing per-share figures with company totals.
  • Using trailing earnings for one company and forward earnings for another.
  • Forgetting dilution from options and convertible securities.

Inputs explained

Field What to enter
Betas of each holding A list of numbers separated by commas, spaces or new lines
Value of each holding A list of numbers separated by commas, spaces or new lines

What each result means

  • Portfolio beta = wavg([Betas of each holding], [Value of each holding])
  • Total portfolio value = sum([Value of each holding])

Formula

Portfolio beta = Σ (weight of holding × beta of holding)Weight = holding value ÷ total portfolio value

Worked example

Inputs — Betas of each holding: 1.3, 0.8, 1.1, 0.6; Value of each holding: 25000, 30000, 20000, 25000.
Results — Portfolio beta = 0.935; Total portfolio value = $100,000.00; Risk compared with the market = About as volatile as the market.

Frequently asked questions

What is portfolio beta?

The weighted average beta of all the investments in a portfolio.

How do I lower my portfolio's beta?

Add low-beta assets such as utilities, bonds or cash.

Does beta measure all risk?

No – only market (systematic) risk.

What formula does the Portfolio Beta Calculator use?

Portfolio beta = Σ (weight of holding × beta of holding).

Cite this calculator

Speedy Calculator. (2026). Portfolio Beta Calculator. Speedy Calculator. https://speedycalculator.com/calculators/finance/portfolio-beta/