Indexed Universal Life (IUL) Calculator 2026: Project Cash Value, Cap Rates & Retirement Income

Indexed universal life is the most heavily illustrated and least understood product in the life insurance market. A single page of an IUL illustration can show a six-figure projected cash value, a tax-free retirement income and a growing death benefit, all from a premium that sounds reasonable — and every one of those numbers rests on assumptions the insurer is allowed to change.

This calculator does something an agent’s illustration will not do for you: it exposes the moving parts. You set the cap rate, the participation rate, the floor and the index assumption yourself, and the tool shows you the illustrated result and the guaranteed result side by side. Set the index assumption to zero percent and watch the guaranteed column become the whole story. That gap is the risk you are actually taking on.

What an IUL Actually Is (and What It Is Not)

An indexed universal life policy is a permanent life insurance contract with two distinct accounts. The first is a death benefit that pays your beneficiaries income-tax-free under IRC section 101(a). The second is a cash value account that the insurer credits with interest tied to a market index — almost always the S&P 500 — according to a formula the insurer sets.

The critical point is that your money is never in the stock market. The insurer buys bonds and other fixed-income assets to back the policy, then pays you a slice of the return it earns, subject to the formula. That structure is why the floor exists: if the index falls 30%, the insurer still earned its bond yield, so it can afford to credit you zero instead of negative thirty. You get downside protection in exchange for giving up the dividend yield the index would have paid and accepting a ceiling on the upside.

What an IUL is not is a security, an index fund, or a retirement account. It is not registered with the SEC, it has no prospectus, and its numbers are not required to be backtested. The illustration an agent hands you is a projection built on assumptions the carrier chooses and can revise. That is not a reason to avoid the product — it is the reason to run the numbers yourself before you sign.

How the Index Credit Is Calculated: Cap, Participation Rate and Floor

Every IUL illustration reduces to one arithmetic chain, applied once per policy year. The index return goes in, three levers are applied in order, and a credited rate comes out. The table below runs the same policy year twice — once when the index rises 14% and once when it falls 20%.

How one policy year is credited — 10% cap, 100% participation rate, 0% floor

Step	Good year (index +14%)	Bad year (index −20%)
1. Index return for the policy year	+14%	−20%
2. Apply participation rate (100%)	14% × 100% = 14%	−20% × 100% = −20%
3. Apply cap (10%)	min(14%, 10%) = 10%	min(−20%, 10%) = −20%
4. Apply floor (0%)	max(10%, 0%) = 10% credited	max(−20%, 0%) = 0% credited

The cap is where IUL illustrations earn their reputation for optimism. In the good year above, the index returned 14% and the policy credited 10% — the policy kept 71% of the index’s gain. In a year the index returns 22%, the policy still credits only 10% and keeps 45% of the move. Meanwhile the participation rate does something subtler: it shrinks your share before the cap applies, so a 50% participation rate on a 14% index year credits only 7% even though the cap is 10%. Two policies with identical caps can behave very differently.

Neither the cap nor the participation rate is guaranteed for the life of the policy in most contracts. Carriers typically reserve the right to lower the cap, the participation rate, or both, subject to a guaranteed minimum disclosed in the contract. That is why the guaranteed column in the calculator above is the number worth reading twice.

What the Calculator Assumes

Every projection needs stated charges, so here are all of them. The tool deducts an annual premium load of 6%, a flat $120 annual policy fee, and a cost of insurance charge calculated from your death benefit and attained age using a simplified mortality table. That cost of insurance is $0.35 per $1,000 of coverage at age 25, $0.85 at 40, $2.80 at 55 and $6.60 at 65, multiplied by 0.80 for women, by 2.50 for tobacco users, and by 0.85 to 1.35 for health class. Whatever remains is credited with interest at the rate produced by your cap, participation rate and floor settings.

What is not modeled: surrender charges, rider costs, optional no-lapse guarantees, and the carrier’s own expense charges beyond the load and fee. Real policies front-load surrender charges of 5% to 10% of cash value for the first ten to fifteen years. If you might need the money inside that window, the projection above is more optimistic than reality.

Projected Cash Value by Index Assumption

Here is the single most useful table on this page. It runs the identical policy — a 40-year-old male preferred non-smoker paying $500 a month for a $500,000 death benefit over 30 years, with a 10% cap, 100% participation rate and 0% floor — at four different index assumptions. Only the assumed index return changes.

Same policy, four assumptions: $500/mo, $500K death benefit, age 40, 30 years (calculator-consistent)

Assumed index return	Credited rate	Cash value at year 30	Gain vs. $180,000 paid	Ratio
0% (floor only)	0.0%	$107,750	−$72,250	0.60×
4%	4.0%	$233,188	+$53,188	1.30×
8% (tool default)	8.0%	$527,235	+$347,235	2.93×
12%	10.0% (capped)	$801,418	+$621,418	4.45×

Notice the first row. A policy that credits its floor every year for thirty years returns $107,750 on $180,000 of premiums — a loss of $72,250, because the premium load, the policy fee and the cost of insurance never stop. This is not a worst case invented for dramatic effect; it is the guaranteed column of a real contract, and it is the reason an IUL is a poor place for money you may need to touch.

Now notice the last row: increasing the assumed index return from 8% to 12% raises the illustrated cash value by more than $274,000. Nothing about the policy changed. Only the assumption changed. Every debate about IUL illustrations is, at bottom, an argument about that row.

How IUL Compares: Whole Life, Term and a Roth IRA

An IUL only makes sense relative to the alternatives, and the alternatives solve different problems. Use this table to find your actual objective before deciding which product to buy.

IUL vs. whole life vs. term vs. Roth IRA — feature comparison

Feature	Indexed Universal Life	Whole Life	Level Term	Roth IRA
Cash value growth	Index-linked, capped	Guaranteed + dividends	None	Market return
Downside protection	Floor, never below 0%	Guaranteed schedule	Not applicable	None
Contribution limit	None (avoid MEC limit)	None (avoid MEC limit)	None	$7,000 / $8,000 if 50+
Cost transparency	Charges disclosed, hard to audit	Fixed premium, opaque dividends	Cheapest per $1,000	Fully transparent
Tax-free access	Policy loans, if not a MEC	Policy loans, if not a MEC	None	After 59½, 5-year rule
Best suited for	Lifelong coverage plus a flexible cash bucket	Predictable, guaranteed permanent coverage	Income replacement for 10–30 years	Retirement savings if you qualify
Main risk	Caps lowered; underfunded lapse	Cost per $1,000 of coverage	Expires with no residual value	Income limits; no death benefit

The honest ranking for most households is unglamorous: buy enough level term to protect your income, fill tax-advantaged retirement accounts, and consider permanent coverage only when you have a permanent obligation — estate liquidity, a business succession plan, a special-needs beneficiary, or a lifelong need for the death benefit. Our term length recommender helps with the first step, and the life insurance vs. investing calculator models the buy-term-and-invest-the-difference alternative directly.

Key Takeaways

• A 10% cap is not a 10% return. The policy crediting 10% in a 14% index year kept 71% of the gain — and in a 22% year it keeps 45%. Participation rates shrink your share even further.
• The floor protects you from the index, not from the charges. A zero-credit year still deducts the premium load, the policy fee and the cost of insurance. Thirty floor-only years cost $72,250 on this illustration.
• Stress-test at 4%, not 8%. The difference between those two assumptions on the same policy is more than $290,000 of projected cash value. Only one of them is a promise.
• Underfunding turns a tax-free asset into a taxable one. If charges outrun premium, the policy lapses — and a lapse with a loan or gain is a taxable event, not a quiet ending.
• Surrender charges can exceed ten years. Money you may need inside the surrender period belongs in a taxable account or a term policy’s saved premium, not in a permanent contract.
• Fill the Roth first if you qualify. An IUL’s advantage is unlimited contributions and a lifelong death benefit, not superior net investment returns.

Seven Steps Before You Buy an IUL

1. Write down the problem the policy solves. If the answer is “I want tax-free retirement income,” try a Roth IRA or a 401(k) first. If the answer is estate liquidity or business succession, the IUL conversation is legitimate.
2. Read the guaranteed column before the illustrated column. Ask for both horizons — the guaranteed illustration and the current illustration. If an agent cannot produce the guaranteed one, that is your answer.
3. Ask what happens if the cap drops two points. Request the identical illustration with a cap two percentage points lower. Most agents can re-run it in minutes; the difference tells you how fragile the projection is.
4. Find the funding premium, not the minimum premium. The minimum keeps the policy alive. The funding premium is what it takes to actually build cash value after charges. They are often far apart.
5. Confirm the surrender charge schedule in writing. Ask for the years and percentages. If you might need liquidity inside ten years, this alone can end the decision.
6. Verify the carrier’s financial strength. Check the rating at AM Best and confirm the insurer is licensed in your state through the NAIC consumer resources.
7. Compare against term plus a taxable account. Run the insurance vs. investing calculator with the same monthly premium. If term plus investing beats the IUL at a 5% assumed return, the IUL has to justify itself on guarantees alone.

Common IUL Mistakes

• Believing the illustrated number. The illustration is a sales document built on the carrier’s chosen assumptions, not a projection of what will happen.
• Buying the minimum premium to “get in.” Chronically underfunded policies are the single most common IUL failure — the cost of insurance quietly consumes the account value.
• Ignoring the MEC line. Contributing too much, too fast turns the contract into a modified endowment contract, which removes the favorable tax treatment on withdrawals and loans.
• Treating cash value as an emergency fund. Between surrender charges and the tax treatment of a lapse, raiding a young policy is expensive. Use our coverage duration calculator to see how real your other assets’ staying power is first.
• Comparing an IUL to an index fund on returns alone. You are not buying the index. You are buying a capped, floored, charge-laden claim on the insurer’s portfolio plus a death benefit.
• Forgetting the death benefit is the point. If a permanent death benefit is not one of your goals, a permanent policy is the wrong tool — see the GUL vs. term comparison for the cheaper permanent alternative.

Watch: IUL Pros and Cons Explained

If the death benefit itself is not a lifelong need, start with the DIME life insurance calculator to size term coverage instead, or the whole life dividend calculator if you want permanent coverage with a guaranteed schedule rather than an index formula.

Frequently Asked Questions

What is an indexed universal life (IUL) policy?

An indexed universal life policy is permanent life insurance whose cash value earns interest linked to a market index, usually the S&P 500, without ever being invested in the market itself. The insurer credits interest using a formula built from three moving parts: a cap rate that limits the upside, a participation rate that sets how much of the index move counts, and a floor that guarantees the credited rate never falls below zero. Because the policy owns both a death benefit and a cash value account, it is priced and regulated as insurance rather than as a security.

Can you lose money in an IUL?

You cannot lose cash value to a negative index year, because the floor credits zero percent instead. But you can lose money in the way that matters: policy charges, the cost of insurance and surrender fees keep being deducted even in a flat year, so a zero-percent credit can still leave your cash value lower than it started. Surrender charges in the first ten to fifteen years, premium loads and rising cost of insurance at older ages are the real ways IUL buyers end up with less than they paid in.

How does the cap rate affect an IUL?

The cap rate is the maximum interest the insurer will credit in one policy year, no matter how high the index goes. A 10% cap means an index return of 14% credits 10%, and an index return of 22% also credits 10%. Caps are not guaranteed for the life of the policy and carriers can often lower them, so the cap printed in today’s illustration is a current rate rather than a permanent promise.

What is a good IUL illustration rate to use?

Use a credited rate well below the cap. If the cap is 10%, projecting an 8% credited rate every single year for thirty years is already optimistic, because the index does not rise every year and the insurer adjusts caps and participation rates over time. Most consumer advocates suggest stress-testing at 4% to 6% and asking the agent to show the same policy with the cap reduced by two percentage points. The calculator on this page defaults to 8% so you can watch the number inflate, then lower the index assumption yourself.

Is an IUL better than a Roth IRA?

They solve different problems. A Roth IRA gives you tax-free growth on after-tax contributions, but contribution limits are low and there are income limits and withdrawal rules. An IUL has no contribution limit, offers tax-free access to cash value through policy loans, and pays a tax-free death benefit, but it carries mortality and expense charges, surrender charges for years, and growth that depends on caps the insurer can change. For most people the efficient answer is to fill the Roth first and use permanent insurance for the specific needs it solves — estate liquidity, a lifelong death benefit, or business succession.

Do you pay taxes on IUL cash value?

Cash value grows tax-deferred, and policy loans are generally not taxable while the policy stays in force and is not a modified endowment contract. Withdrawals and loans become taxable if the policy lapses or is surrendered with a gain, because the gain is then treated as ordinary income. The death benefit is paid to beneficiaries free of federal income tax under IRC section 101(a). That is why lapse risk matters so much: a policy that dies from insufficient funding converts a tax-free asset into a taxable event.

Why is the guaranteed column so much lower than the illustrated column?

The guaranteed column credits only the policy floor, typically zero or one percent, every year. Everything the illustrated column adds above that comes from non-guaranteed assumptions about future index performance, future cap rates and future participation rates. Carriers must show both columns precisely because the difference is the risk the buyer carries. Read the guaranteed column first — it is the only number the insurer is contractually obligated to deliver.

How much does an IUL cost per month?

The cost of an IUL is whatever premium you choose, because it is a flexible-premium policy — but there is a minimum required to keep the death benefit in force and a maximum before the policy becomes a modified endowment contract. Inside the premium, a load of roughly 5% to 10% comes off the top, a fixed policy fee is deducted, and the cost of insurance rises every year with your age. This calculator applies a 6% load, a $120 annual fee and age-based mortality charges so you can see how much of each premium actually reaches the cash value.

Related Resources

• AM Best — insurance carrier financial-strength ratings
• NAIC — consumer insurance resources and policyholder protections
• IRS Publication 525 — taxation of life insurance death benefits and policy loans
• SEC Investor.gov — indexed universal life insurance glossary entry

Our free MEC 7-pay test calculator shows how much premium an overfunded IUL can absorb before the IRS reclassifies it as a Modified Endowment Contract.