Calculator Inputs
Example Data Table
| Scenario | Paid Losses | Case Reserves | LDF | Expected LR | Suggested Method |
|---|---|---|---|---|---|
| Newer accident year | 1,200,000 | 900,000 | 2.10 | 68% | Bornhuetter Ferguson |
| Mature accident year | 3,800,000 | 350,000 | 1.08 | 62% | Chain Ladder |
| Mixed credibility year | 1,850,000 | 740,000 | 1.42 | 66% | Credibility Blended |
Formula Used
Incurred Losses = Paid Losses + Case Reserves
Chain Ladder Ultimate = Incurred Losses × Selected Development Factor
Expected Ultimate = Earned Premium × Expected Loss Ratio
Bornhuetter Ferguson Ultimate = Incurred Losses + Expected Ultimate × (1 - 1 / LDF)
Blended Ultimate = Credibility × Chain Ladder Ultimate + (1 - Credibility) × Bornhuetter Ferguson Ultimate
Gross IBNR = Selected Ultimate Loss - Incurred Losses
Gross Unpaid Reserve = Selected Ultimate Loss - Paid Losses
Net Indicated Reserve = Gross Reserve + Expenses + Risk Margin - Reinsurance Credit
How to Use This Calculator
Enter the valuation date and accident year first. Add earned premium and exposure units for the selected book. Enter paid losses, case reserves, claim counts, and average claim size. Select a loss development factor based on your actuarial triangle or judgment. Add the expected loss ratio, credibility weight, expenses, risk margin, and reinsurance recovery. Choose the reserve method. Press the calculate button. The result appears above the form and below the header.
Actuary Loss Reserve Planning Guide
Purpose of Loss Reserves
Loss reserves estimate the future cost of claims already incurred. They help insurers hold enough funds for unpaid losses. The estimate includes known case reserves and claims not yet reported. It may also include claim adjustment expenses, margin, and reinsurance effects.
Why Actuarial Inputs Matter
Each input changes the reserve result. Paid losses show cash already settled. Case reserves show known unpaid claim amounts. Development factors project immature claims to ultimate levels. Earned premium supports expected loss methods. Credibility weights decide how much trust is placed on actual experience.
Common Reserve Methods
The chain ladder method works well when claim development is stable. It uses current incurred losses and applies a development factor. The expected loss ratio method is useful when experience is thin. It relies on premium and a selected loss ratio. The Bornhuetter Ferguson method blends actual emergence with expected losses. This is useful for newer accident years.
Expense and Margin Review
Reserve work should not stop at unpaid losses. Claims often need defense costs, adjusting costs, and internal handling costs. ALAE and ULAE ratios add these items. Risk margins add prudence for uncertainty. The confidence multiplier increases the margin when management wants a stronger reserve position.
Interpreting the Result
The selected ultimate loss is the projected final claim cost. Gross IBNR is the hidden unpaid amount beyond current incurred losses. Gross unpaid reserve is the amount still expected after paid losses. Net indicated reserve adjusts the total for expenses, margin, and reinsurance credit.
Practical Use
Use this calculator for planning, review, and sensitivity testing. It is not a replacement for a signed actuarial opinion. Real reserve work may require claim triangles, exposure trends, inflation, large loss review, and regulatory standards. Still, this tool gives a clear reserve framework for quick analysis.
FAQs
What is a loss reserve?
A loss reserve is money set aside for unpaid claims. It includes known case reserves and estimated future claim amounts.
What does IBNR mean?
IBNR means incurred but not reported. It estimates claims that happened but are not fully reported or developed yet.
Which method should I choose?
Use chain ladder for mature data. Use expected loss for thin data. Use Bornhuetter Ferguson for newer years. Use blended for balanced judgment.
What is a development factor?
A development factor projects current losses to ultimate losses. Larger factors usually mean the accident year is less mature.
Why include ALAE and ULAE?
Claims create handling costs. ALAE covers claim-specific adjustment costs. ULAE covers broader claim department and administrative costs.
What is the confidence multiplier?
It increases the risk margin for uncertainty. A higher value creates a more conservative reserve indication.
Does reinsurance reduce reserves?
Reinsurance can reduce the net reserve after recoveries. Gross reserves should still be reviewed before applying credits.
Can this replace actuarial review?
No. It supports estimates and sensitivity testing. Formal reserve opinions need deeper data, methods, documentation, and professional judgment.