Conditional VaR Calculator

Estimate tail losses beyond your chosen confidence level. Compare historical, parametric, and simulation approaches quickly. Export results, audit inputs, and strengthen risk decisions today.

Calculator Inputs

Choose your tail estimation approach.
Common values: 0.95, 0.975, 0.99.
Used to convert returns into currency losses.
Set 1 for daily. Use your data cadence.
Used by parametric and simulation methods.
Standard deviation of returns.
Higher improves tail stability (slower).
Set for reproducible simulation results.
Accepts decimals or percentages (e.g., 1.2%).
Reset

Example Data Table

Sample daily returns you can paste into the Historical field.

Day Return Notes
10.0040Small gain
2-0.0065Moderate loss
30.0022Rebound
4-0.0120Tail event
50.0015Stabilization
Tip: use at least 30–250 observations for stable tails.

Formula Used

Core definition
CVaRα = E[L | L ≥ VaRα]
L is the loss random variable, α is the confidence level.
Parametric (Normal) loss model
L = -V · Rh,  Rh ~ N(μh, σ√h)
VaRα = μL + σL · zα
CVaRα = μL + σL · φ(zα)/(1-α)
zα is the inverse normal CDF; φ is the normal PDF.
Historical / Monte Carlo tail
Compute losses, take the α-quantile as VaR, then average losses in the tail beyond that threshold.

How to Use

  1. Pick a method: Parametric, Historical, or Monte Carlo.
  2. Set confidence level, portfolio value, and horizon days.
  3. For Historical, paste returns (one per line or comma-separated).
  4. For Simulation, choose simulations and optional random seed.
  5. Click calculate to view VaR and Conditional VaR above.
  6. Use CSV or PDF buttons to export your results.

Conditional VaR in loss-tail decisions

Conditional VaR (CVaR), called Expected Shortfall, estimates the average loss once portfolio losses exceed the VaR cutoff. It complements VaR by capturing tail severity rather than only a single quantile. Risk teams use CVaR to compare strategies with similar volatility but different downside profiles, and to set limits that reflect extreme-loss behavior. In reporting, CVaR is typically expressed in currency, aligning with budgeted loss capacity.

Confidence level and tail size

The confidence level α controls how much data falls into the tail: tail probability equals (1−α). For α=0.95, roughly 5% of scenarios define the tail mean; for α=0.99, about 1% do. Higher α generally increases VaR and CVaR, but CVaR can grow faster because it averages the worst outcomes. A practical check is tail count: too few tail points makes CVaR noisy and sensitive to single shocks.

Estimation methods and inputs

Parametric estimation assumes returns follow a normal distribution with mean μ and volatility σ, producing a closed-form VaR and CVaR. Historical estimation uses observed returns directly, ranking the implied losses and averaging those beyond the VaR threshold. Monte Carlo simulates many return scenarios from μ and σ, then computes an empirical tail; more simulations improve stability but cost time. Method choice should reflect data quality and tail realism.

Portfolio scaling and horizon handling

This calculator converts returns to losses using L = −V·R, where V is portfolio value and R is the horizon return. Under standard scaling, expected return grows with the number of days h, while volatility grows with √h. If your returns are already horizon-aligned, keep h=1 to avoid double scaling. For multi-asset portfolios, V should reflect valuation and include any relevant leverage or notional adjustments.

Interpreting outputs for controls

VaR is the loss threshold exceeded with probability (1−α); CVaR is the expected loss given that threshold is breached. If CVaR is much larger than VaR, the tail is heavy, implying larger conditional losses during stress. Review worst-loss and average-loss diagnostics to detect outliers or regime shifts. Use CVaR alongside stress tests, concentration checks, and model validation before setting limits, capital buffers, or escalation triggers.

FAQs

What is the difference between VaR and Conditional VaR?

VaR is a loss cutoff at confidence α. Conditional VaR is the average loss of outcomes that are worse than VaR, so it reflects tail severity rather than only a threshold.

Which method should I choose for daily risk reporting?

Use parametric for fast, stable estimates when returns are near-symmetric. Use historical when you trust your return history and want empirical tails. Use Monte Carlo when you need scenario volume and controlled assumptions.

How many historical returns do I need?

At least 30 observations are required here, but 250+ daily points is better. Higher confidence levels need more data, because the tail contains fewer points and the tail mean becomes unstable.

Why does Conditional VaR increase faster than VaR?

VaR selects one quantile. Conditional VaR averages losses beyond that quantile. If the tail is heavy, the worst losses rise quickly, pushing the conditional average up more than the cutoff.

How does horizon affect the numbers?

With standard scaling, expected return scales with h and volatility with √h. Larger horizons usually increase both VaR and Conditional VaR in currency terms, especially when volatility dominates the drift term.

Can I export results for audit trails?

Yes. After running a calculation, use the CSV and PDF buttons in the results card. Exports include method, inputs, VaR, Conditional VaR, and a scenario-loss preview for traceability.


Notes: This tool is for educational and planning use. Validate assumptions, data quality, and model fit before making operational decisions.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.