Risk Analysis Tool

How to Calculate Portfolio Risk - Portfolio Volatility & Standard Deviation Calculator

Learn how to calculate portfolio risk, volatility, and standard deviation with our free calculator and formula guide. Calculate portfolio volatility, standard deviation of portfolio, portfolio variance, and investment risk. Use our portfolio volatility calculator, standard deviation of portfolio calculator, and investment risk calculator to measure risk using Modern Portfolio Theory. Formula: σp = √(w₁²σ₁² + w₂²σ₂² + 2w₁w₂σ₁σ₂ρ). Our calculator helps investors assess portfolio risk using asset allocation analysis, correlation modeling, and risk-adjusted return calculations for optimal diversification strategies.

Last updated: February 2, 2026

Portfolio volatility calculation
Sharpe ratio analysis
Diversification benefit measurement

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Portfolio Risk Calculator
Measure portfolio diversification and risk metrics

Asset Allocation (%)

Total: 100.0%

Risk Parameters

Annual standard deviation (typical: 15-20% for stocks)

Annual standard deviation (typical: 4-8% for bonds)

Correlation between stocks and bonds (-1 to 1, typical: 0.1-0.3)

Risk Analysis

Risk Level

Moderate Risk

Portfolio Volatility

11.30%

annual standard deviation

Sharpe Ratio

0.37

Max Drawdown

28.2%

Diversification Benefit

1.30%

risk reduction from diversification

Analysis:

Balanced portfolio with appropriate risk-return profile.

Portfolio Risk Formula:

  • • σp² = ws²σs² + wb²σb² + 2wswbσsσbρ
  • • Lower correlation = better diversification
  • • Sharpe Ratio = (Return - Risk-Free) / Volatility
  • • Volatility measures portfolio uncertainty

How to Calculate Portfolio Risk - Step by Step Guide & Formula

Portfolio Risk Formula

Main Formula:

σp = √(w₁²σ₁² + w₂²σ₂² + 2w₁w₂σ₁σ₂ρ₁₂)

Where:
  • • σp = Portfolio standard deviation
  • • w₁, w₂ = Asset weights
  • • σ₁, σ₂ = Asset volatilities
  • • ρ₁₂ = Correlation (-1 to +1)
Example:
  • • 60% stocks (18% vol)
  • • 40% bonds (6% vol)
  • • Correlation: 0.2
  • • Portfolio Risk: 11.3%

Step-by-Step: How to Calculate Portfolio Risk

Step 1: Determine Asset Weights

Calculate the percentage allocation for each asset:

Weight = Asset Value ÷ Total Portfolio Value

Example: $60,000 stocks ÷ $100,000 total = 60% (w₁ = 0.60)

$40,000 bonds ÷ $100,000 total = 40% (w₂ = 0.40)

Step 2: Get Individual Asset Volatilities

Find standard deviation (volatility) for each asset:

  • • Stocks: Typically 15-20% annual volatility
  • • Bonds: Typically 4-8% annual volatility
  • • Cash: 0% volatility
  • • Convert percentages to decimals: 18% = 0.18

Step 3: Find Asset Correlations

Determine correlation coefficient between assets:

  • • Range: -1 (perfect opposite) to +1 (perfect together)
  • • Stocks-Bonds: Typically 0.1-0.3 (slightly positive)
  • • Lower correlation = better diversification
  • • Negative correlation = best diversification

Step 4: Calculate Portfolio Variance

Apply the variance formula:

σp² = w₁²σ₁² + w₂²σ₂² + 2w₁w₂σ₁σ₂ρ

Example: 0.6²×0.18² + 0.4²×0.06² + 2×0.6×0.4×0.18×0.06×0.2 = 0.0128

Step 5: Calculate Portfolio Standard Deviation

Take the square root of variance:

σp = √Variance

Example: √0.0128 = 0.113 = 11.3% portfolio risk

Portfolio Risk Calculation Example

Example: 60/40 Stock/Bond Portfolio

Given: 60% stocks (18% volatility), 40% bonds (6% volatility), 0.2 correlation
Step 1: Portfolio Variance = 0.6²×0.18² + 0.4²×0.06² + 2×0.6×0.4×0.18×0.06×0.2
Step 2: Variance = 0.0117 + 0.0006 + 0.0005 = 0.0128
Step 3: Portfolio Standard Deviation = √0.0128 = 0.113 = 11.3%
Result: Portfolio Risk = 11.3%
Diversification Benefit: Weighted average (13.2%) - Portfolio risk (11.3%) = 1.9% reduction

Key Insight: Portfolio risk (11.3%) is lower than the weighted average (13.2%) due to diversification. This demonstrates how combining assets with low correlation reduces overall portfolio risk.

Portfolio Risk Calculator Types & Investment Analysis Tools

Portfolio Volatility Calculator
Calculate portfolio standard deviation and variance

Measures

Std Dev, Variance

Quantifies portfolio return uncertainty

Sharpe Ratio Calculator
Measure risk-adjusted returns and portfolio efficiency

Formula

(Return - RF) / σ

Evaluates returns relative to risk taken

Portfolio Diversification Calculator
Analyze diversification benefits and correlation

Correlation

-1 to +1

Measures how assets move together

Asset Allocation Risk Calculator
Evaluate risk across different asset mixes

Asset Classes

Stocks, Bonds, Cash

Optimizes allocation for risk tolerance

Maximum Drawdown Calculator
Estimate worst-case portfolio decline scenarios

Estimate

2-3× Volatility

Projects potential peak-to-trough losses

Modern Portfolio Theory Calculator
Apply MPT principles for optimal portfolios

Concept

Efficient Frontier

Maximizes return for given risk level

Standard Deviation of Portfolio Calculator
Calculate portfolio standard deviation (volatility) using variance-covariance method

Formula

σp = √(w₁²σ₁² + w₂²σ₂² + 2w₁w₂σ₁σ₂ρ)

Calculates portfolio volatility accounting for correlations

Investment Risk Calculator
Measure investment risk, volatility, and risk-adjusted returns

Risk metrics

Volatility, Sharpe Ratio

Comprehensive investment risk analysis

Quick Example Result

60/30/10 stocks/bonds/cash allocation with 18%/6% volatilities:

Portfolio Volatility

11.30%

Risk Level

Moderate Risk

How Our Portfolio Risk Calculator Works

Our portfolio risk calculator applies Modern Portfolio Theory to measure investment risk through volatility, correlation, and diversification analysis. The calculation uses variance-covariance methodology to determine portfolio risk metrics, helping investors optimize asset allocation for their risk tolerance and financial goals.

Portfolio Risk Formula - Complete Guide

Main Portfolio Risk Formula:

σp = √(w₁²σ₁² + w₂²σ₂² + 2w₁w₂σ₁σ₂ρ₁₂)

Where: w = asset weights, σ = volatilities, ρ = correlation

Additional Formulas:

Portfolio Variance = w₁²σ₁² + w₂²σ₂² + 2w₁w₂σ₁σ₂ρ
Sharpe Ratio = (Rp - Rf) / σp
Diversification Benefit = Weighted Avg Vol - Portfolio Vol

Quick Calculation Example:

Given: 60% stocks (18% vol), 40% bonds (6% vol), 0.2 correlation
Step 1: Portfolio Variance = 0.6²×0.18² + 0.4²×0.06² + 2×0.6×0.4×0.18×0.06×0.2
Step 2: Variance = 0.0117 + 0.0006 + 0.0005 = 0.0128
Step 3: Portfolio Standard Deviation = √0.0128 = 0.113 = 11.3%
Result: Portfolio Risk = 11.3% (lower than 13.2% weighted average due to diversification)

The calculator uses the variance-covariance method to compute portfolio volatility, accounting for individual asset risks and their correlations. Lower correlation between assets provides better diversification, reducing portfolio risk below the weighted average of individual asset risks—the fundamental insight of Modern Portfolio Theory.

📊 Efficient Frontier Diagram

Shows optimal portfolios balancing risk and return along the efficient frontier

Mathematical Foundation

Portfolio risk calculation is based on Modern Portfolio Theory developed by Harry Markowitz (Nobel Prize 1990). The theory demonstrates that portfolio risk depends not just on individual asset risks but critically on correlations between assets. Combining uncorrelated or negatively correlated assets reduces overall portfolio volatility—diversification is the only "free lunch" in investing. The efficient frontier represents optimal portfolios offering maximum return for each risk level, and the Sharpe ratio identifies the portfolio with best risk-adjusted returns.

  • Portfolio volatility measures total portfolio return uncertainty
  • Lower correlation between assets improves diversification
  • Sharpe ratio evaluates returns relative to risk taken
  • Maximum drawdown estimates worst-case decline scenarios
  • Diversification reduces risk without sacrificing expected returns
  • Optimal portfolios lie on the efficient frontier curve

Sources & References

  • Portfolio Selection - Harry Markowitz (1952)Seminal paper introducing Modern Portfolio Theory
  • The Intelligent Asset Allocator - William BernsteinPractical guide to portfolio construction and risk management
  • CFA Institute - Portfolio Management StandardsProfessional standards for investment risk analysis

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Portfolio Risk Examples

Balanced Portfolio Risk Example
60/30/10 stocks/bonds/cash allocation with correlation analysis

Portfolio Inputs:

  • Stocks: 60% at 18% volatility
  • Bonds: 30% at 6% volatility
  • Cash: 10% at 0% volatility
  • Stock-Bond Correlation: 0.2

Risk Metrics:

  • Portfolio Volatility: 11.30%
  • Undiversified Risk: 13.2%
  • Diversification Benefit: 1.30%
  • Sharpe Ratio: 0.37

Result: Moderate risk portfolio with moderate risk

Diversification reduces risk by 1.30% compared to undiversified portfolio. Expected max drawdown: approximately 28.2% during severe market downturns.

Conservative Portfolio

30/60/10 stocks/bonds/cash

Risk: ~7% volatility

Aggressive Portfolio

90/10/0 stocks/bonds/cash

Risk: ~17% volatility

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