Introduction
A premium must fund more than expected claims. It also covers expenses, and a rate may include an amount intended to remain after those costs are paid. That intended amount is the underwriting profit provision. It is a component of the indicated premium, not a guarantee that the insurer will earn that amount: realized losses and expenses can differ from their estimates.
The central calculation is to solve for the premium that covers expected losses, expenses, and a target profit expressed as a share of premium. Keeping the premium-based components tied to the premium, rather than to losses, is essential to getting the indicated amount right. The examples below assume a simple one-period setting with no investment income, taxes, or other provisions.
Building the Premium Equation
Let \(L\) be the expected losses for the policy or group being priced, and let \(F\) be expenses specified as a fixed dollar amount for that same unit. Let \(v\) be the variable expense rate, meaning the share of premium used for expenses that vary with premium. Let \(\pi\) be the target underwriting profit provision as a share of premium. The gross premium \(P\) must fund all four components.
The model assumes that expected losses and fixed expenses are dollar amounts for the same exposure basis as the premium, while variable expenses and the profit provision are each constant percentages of that premium. It also assumes \(1-v-\pi>0\); otherwise, the premium-based expense and profit shares together leave no positive share of premium to fund losses and fixed expenses. Under these assumptions:
Solving for the gross premium gives:
The formula does not apply unchanged if a purported expense is not actually a fixed amount or a percentage of premium, or if the selected profit target is a fixed dollar amount rather than a share of premium. Those items require a different equation. Any other provision included in the premium would also need to be represented explicitly rather than silently treated as profit.
Why the Profit Share Changes the Denominator
The denominator follows directly from the funding equation. Start with the amount left after premium-based expenses and the profit provision are removed from premium: \(P-vP-\pi P\). This must equal the expected losses and fixed expenses, \(L+F\). Factoring out \(P\) gives \(P(1-v-\pi)=L+F\), and dividing by the positive quantity \(1-v-\pi\) yields the indicated premium.
This derivation explains an important feature: \(\pi\) is a proportion of the gross premium, not a markup on expected losses or on losses plus fixed expenses. Adding \(\pi\) to the numerator would use a different base and would not produce a profit equal to \(\pi P\).
Use expected losses and fixed expenses for the same policy, exposure, or group whose premium is being determined.
Write the variable expense rate and target profit provision as proportions of gross premium.
Calculate \(P\), then separately calculate variable expenses \(vP\) and the profit provision \(\pi P\). Confirm that all components sum to \(P\).
Worked Premium Calculations
Worked Example: Indicating a Premium for One Policy
A hypothetical equipment policy has expected losses of $510 and fixed policy expenses of $42. Variable expenses are 9% of premium, and the selected underwriting profit provision is 7% of premium. Find the indicated premium and verify the allocation. Report the premium and dollar components to the nearest cent.
Method. The losses and fixed expense are dollar amounts, while both variable expenses and the profit provision are premium shares. Thus \(L=510\), \(F=42\), \(v=0.09\), and \(\pi=0.07\). The denominator is \(1-0.09-0.07=0.84\), which is positive.
The amount to be funded by the part of premium left after the two percentage provisions is \(510+42=552\). Therefore:
Rounded to the nearest cent, the indicated premium is $657.14. The variable expense is \(0.09(657.142857\ldots)=$59.142857\ldots\), or $59.14 to the cent. The profit provision is \(0.07(657.142857\ldots)=$46.00\). Using unrounded amounts for the check:
The components reconcile to the unrounded premium. The common mistake this method avoids is adding 7% to the $552 numerator: the 7% target is a share of the premium, not a share of $552.
Worked Example: Pricing a Small Policy Group
A hypothetical group of three similar policies has aggregate expected losses of $2,250. Fixed expenses are $45 per policy. Variable expenses are 11% of premium, and the target profit provision is 6% of premium. Find the indicated group premium and premium per policy. Report dollar amounts to the nearest cent.
Method. First convert the fixed expense to the group basis: \(3(45)=$135\). The expected losses are already aggregate, so \(L+F=2,250+135=$2,385\). The percentage provisions total \(0.11+0.06=0.17\), leaving \(1-0.17=0.83\) of premium to fund the dollar amounts.
The indicated group premium is $2,873.49. Dividing the unrounded group premium by three gives \(2,873.493975\ldots/3=$957.831325\ldots\), or $957.83 per policy to the nearest cent.
For a check, variable expenses are \(0.11(2,873.493975\ldots)=$316.084337\ldots\), and the profit provision is \(0.06(2,873.493975\ldots)=$172.409639\ldots\). Adding the unrounded components gives:
The fixed expense must be multiplied by three because the loss amount and premium are for three policies. Using $45 as the group fixed expense would mix per-policy and group bases and understate the indicated premium.
Provision Versus Realized Underwriting Gain
The profit provision is selected using expected losses and expenses. Once a period has occurred, the underwriting gain is found from actual premium and actual costs. In this simple model, actual gain equals actual premium minus actual losses, fixed expenses, and variable expenses. If actual variable expenses remain a proportion \(v\) of actual premium, that expense is \(vP\). This accounting identity does not say that actual gain will equal the provision: the actual losses, fixed expenses, premium, or variable expense rate may differ from the pricing assumptions.
Worked Example: Actual Results Compared With the Selected Provision
A hypothetical two-policy group is priced using expected losses of $400 per policy, fixed expenses of $30 per policy, variable expenses of 10% of premium, and a profit provision of 8% of premium. Actual aggregate losses are $900. Assume the two fixed expenses are incurred as selected and actual variable expenses are 10% of premium. Find the indicated group premium, the selected profit provision, and the actual underwriting gain. Report dollar amounts to the nearest cent.
Method. Aggregate expected losses are \(2(400)=$800\), and aggregate fixed expenses are \(2(30)=$60\). The premium denominator is \(1-0.10-0.08=0.82\). Therefore:
The indicated premium is $1,048.78 to the nearest cent. The selected profit provision is \(0.08(1,048.780487\ldots)=$83.902439\ldots\), or $83.90. Actual variable expenses are \(0.10(1,048.780487\ldots)=$104.878049\ldots\). Actual underwriting gain is:
Thus the actual result is an underwriting loss of $16.10, not the selected positive provision of $83.90. The check is that actual losses exceed expected losses by \(900-800=$100\); the selected expected gain of approximately $83.90 is reduced by $100, giving an actual result of approximately \(-$16.10\). The method avoids treating a provision in a rate as a guaranteed realized gain.
Common Calculation Trap
A tempting but incorrect shortcut is to increase the loss-and-fixed-expense amount by the two percentages. In the first example, that shortcut gives \(552(1+0.09+0.07)=$640.32\). But at a premium of $640.32, the variable expense and profit provision together are only \(0.16(640.32)=$102.4512\). Adding the $552 of losses and fixed expenses produces $654.4512, not $640.32. The proposed premium does not fund its own components.
The correction is to recognize that each percentage is applied to the unknown gross premium. Solve \(P=552+0.09P+0.07P\), giving \(P=552/0.84=$657.142857\ldots\). The verification is decisive: the correct premium equals the sum of losses, fixed expenses, variable expenses, and the profit provision. Keeping that check in the calculation catches both denominator errors and inconsistent exposure bases.
Check Your Understanding
For each problem, use the stated simple model and keep the premium basis consistent.
- A hypothetical bicycle policy has expected losses of $360, fixed expenses of $24, variable expenses of 8% of premium, and a target profit provision of 10% of premium. Find the indicated premium to the nearest cent. (Answer: $468.29)
- A hypothetical group has aggregate expected losses of $1,400 and fixed expenses of $120. Variable expenses are 12% of premium, and the profit provision is 6% of premium. Find the indicated group premium and dollar profit provision, each to the nearest cent. (Answer: Premium $1,853.66; profit provision $111.22)
- A policy has earned premium of $950, actual losses of $610, fixed expenses of $70, and variable expenses equal to 14% of premium. Calculate the actual underwriting gain. How much greater or smaller is it than a target provision of 8% of premium? (Answer: Actual gain $137.00; it is $61.00 greater than the $76.00 target provision.)
- A hypothetical policy group has a premium of $1,200, expected losses of $760, fixed expenses of $100, and variable expenses of 12% of premium. What profit provision rate is represented by this premium? (Answer: 16.33% of premium)
- A hypothetical coverage has expected losses of $900, fixed expenses of $90, variable expenses of 15% of premium, and a target profit provision of 5% of premium. Find the indicated premium and profit provision to the nearest cent, and verify the funding equation. (Answer: Premium $1,237.50; profit provision $61.88; \(900+90+185.625+61.875=1,237.50\).)