What DIME is trying to answer
Life insurance replaces a financial contribution, not a person. The question DIME answers is narrow and answerable: if your income stopped today, how large a lump sum would your household need to stay solvent and meet the commitments you had made? Four buckets cover most of it.
D — Debt and final expenses. Every obligation that survives you, plus the immediate cost of a funeral and estate administration. Unsecured debts do not simply vanish; they are claims against the estate, and in community property states a surviving spouse may be liable for some of them directly.
I — Income replacement. The largest leg for most households, and the only one that requires a judgement about time and return rather than a balance from a statement.
M — Mortgage. The outstanding payoff balance, so the family can either clear the loan or continue paying it from the proceeds.
E — Education. What you intend to make available per child. This is a goal rather than an obligation, which is why it is the leg most often trimmed when the premium comes back too high.
Then subtract what already exists. In-force policies, employer group cover and liquid assets all reduce the gap. The output is the additional death benefit to buy — and because term insurance is priced roughly in proportion to the face amount, it converts directly into a premium quote.
DIME is a rule-of-thumb framework, not an actuarial standard. Its virtue is that every input is a number you can look up rather than estimate, which makes the answer arguable in a useful way. Its weakness is that it is deliberately conservative in one specific place, discussed below.
The income leg, and why the discount rate matters more than anything else
Three of the four legs are balances you read off a statement. The income leg is the one that requires a model, and it is usually more than half the answer.
The naive version multiplies: $59,500 a year for 15 years is $892,500. That is correct only if the payout sits in a non-interest-bearing account and inflation is zero. In practice the family invests the lump sum and draws it down, so you need the present value of an annuity:
PV = A × (1 − (1 + r)^−n) ÷ r
The rate r here must be a real rate — return after inflation — because the income being replaced also grows with inflation. Mixing a nominal return with constant nominal withdrawals understates the need substantially, and it is the most common error in a homemade needs analysis. A 2% real rate is a defensible conservative assumption for a portfolio that must be safe and liquid; anything above 4% real implies an equity allocation that a household drawing income for immediate living costs probably cannot carry.
The effect is large. At 2% real, 15 years of $59,500 has a present value of $764,530.73 rather than $892,500 — a reduction of $127,969.27, or 14.3%. At 4% real it falls to 11.118387 × 59,500 = $661,544, a reduction of 25.9% from the undiscounted figure. Those differences are bigger than most people's entire education leg, which is why the discount rate deserves as much attention as the income figure.
Now the deliberate conservatism. DIME funds the mortgage payoff and replaces the income that was paying the mortgage, so the housing payment is covered twice. That is a real overlap, and it is defensible as a safety margin — but it should be a decision, not an accident. If you want to remove it, reduce the replacement percentage by the share of gross income going to the mortgage payment. A household paying 22% of gross toward the mortgage would drop from 70% replacement to about 48% while keeping the M leg intact.
Worked example: $85,000 income, two children, $280,000 mortgage
You earn $85,000, want to replace 70% of it for 15 years, assume a 2% real return, carry a $280,000 mortgage and $25,000 of other debt, allow $12,000 for final expenses, want $110,000 available for each of two children, and already hold $100,000 of cover and $60,000 of liquid assets.
- Annual income to replace. 85,000 × 0.70 = $59,500.00.
- Present value factor. 1.0215 = 1.3458705, so (1 − 1 ÷ 1.3458705) ÷ 0.02 = (1 − 0.7430149) ÷ 0.02 = 0.2569851 ÷ 0.02 = 12.8492559.
- Income leg (I). 59,500 × 12.8492559 = $764,530.73.
- Debt and final expenses (D). 25,000 + 12,000 = $37,000.00.
- Mortgage (M). $280,000.00.
- Education (E). 2 × 110,000 = $220,000.00.
- Total need. 37,000 + 764,530.73 + 280,000 + 220,000 = $1,301,530.73.
- Existing resources. 100,000 + 60,000 = $160,000.00.
- Additional coverage. 1,301,530.73 − 160,000 = $1,141,530.73, which is 13.4 times gross income.
Round that to a $1.2 million 15-year level term policy, matching the term to the years of income replaced. Two sanity checks are worth doing. First, the income leg is 764,530.73 ÷ 1,301,530.73 = 58.7% of the total need, which is typical — if yours is far below half, check whether the years or the replacement percentage are too low. Second, the common rule of thumb of ten to twelve times income would have given $850,000 to $1,020,000 here, materially less than DIME, because the rule of thumb ignores the mortgage and education entirely.
Now test a lever. Dropping the replacement percentage from 70% to 60% cuts the annual need to $51,000 and the income leg to 51,000 × 12.8492559 = $655,312.05, a reduction of $109,218.68 and about 9.6% off the additional coverage figure. Cutting the years from 15 to 10 instead uses a factor of 8.9825850, giving 59,500 × 8.9825850 = $534,463.81 and a reduction of $230,066.92. The years lever is roughly twice as powerful as the ten-point percentage lever here — but note that this comparison holds for these particular sizes of change, not in general; a 20-point cut in the percentage would beat a five-year cut in the term.
Present value factors for income replacement
| Years replaced | 0% real | 2% real | 3% real | 4% real |
|---|---|---|---|---|
| 10 | 10.000000 | 8.982585 | 8.530203 | 8.110896 |
| 15 | 15.000000 | 12.849256 | 11.937935 | 11.118387 |
| 20 | 20.000000 | 16.351433 | 14.877475 | 13.590326 |
| 25 | 25.000000 | 19.523456 | 17.413148 | 15.622080 |
| 30 | 30.000000 | 22.396456 | 19.600441 | 17.292033 |
Read across a row to see the cost of an optimistic return assumption. At 20 years, moving from 2% to 4% real cuts the multiplier from 16.35 to 13.59 — a 16.9% reduction in the income leg on nothing but an investment forecast.
Turning the number into a policy
Match the term to the years of income you are replacing, then round the face amount up rather than down. Term life is priced close to linearly in the face amount at ordinary sizes, so rounding $1,141,531 up to $1,200,000 costs a few percent more and removes the need to revisit the figure for a while. Level term is the right product for a DIME need because the need itself declines over time — the mortgage amortises, the children get older, the income years run down — while the premium stays flat.
Where the calculated need is uncomfortably large, work the levers in this order. Reduce the education leg first, because it is a goal rather than an obligation and because scholarships, savings and the child's own earnings can fill part of it. Then examine the replacement percentage against the mortgage overlap described above. Only then reduce the years, because shortening the term is the change most likely to leave a genuine gap.
Consider laddering rather than buying one policy. Two policies — say $700,000 for 20 years and $500,000 for 10 — cost less than $1.2 million for 20 years and track a declining need more closely. The trade is complexity and two sets of policy fees.
Count employer group cover carefully. It is genuine while you hold the job and worthless the day you leave, and the coverage is usually a multiple of salary that shrinks relative to a growing need. Cover above $50,000 also creates imputed income on your W-2, which the group-term life imputed income calculator quantifies. Treating group cover as permanent is the most common way a needs analysis understates the gap.
Finally, note what DIME does not size at all. It is a death benefit calculation, and the more likely event for a working-age adult is disability rather than death. A household that has bought $1.2 million of term life and holds no disability cover has insured the less probable of two similar financial losses; the disability insurance benefit calculator sizes the other one.
Assumptions and limits worth knowing
- The mortgage is funded twice. Deliberately — the M leg pays it off and the I leg replaces the income that was servicing it. Adjust the replacement percentage if you want the overlap removed.
- Survivor benefits are not netted off. Social Security survivor benefits for children and a caring spouse can be substantial and would reduce the income leg; DIME ignores them, which adds margin.
- The income stream is level. Real needs decline as children leave home and the mortgage amortises, so a level annuity slightly overstates a household's true profile.
- A non-earning spouse's contribution is not included. Childcare and household work have a real replacement cost, and DIME as written captures none of it. Cover on a non-earning spouse should be sized on that cost instead.
- Education cost is entered in today's money. Since the discount rate is real, that is internally consistent — but only if the figure you enter is a current cost of attendance, not a projected one.
- Estate tax is not modelled. Death benefits are generally free of income tax under IRC §101(a), but policy proceeds are included in the taxable estate where the insured owned the policy.
- No allowance for a rising income. If your earnings are growing faster than inflation, the real replacement need grows too, and the answer should be revisited every few years.
Death benefits are income tax free, but not always estate tax free
Under IRC §101(a), life insurance proceeds paid by reason of the insured's death are excluded from the beneficiary's gross income, so there is no need to gross up the face amount for income tax. Estate tax is a different question. If the insured owned the policy or held any incident of ownership in it, the death benefit is included in the gross estate for federal estate tax purposes even though the beneficiary receives it income tax free. Households near the federal exemption commonly address this by having the policy owned by an irrevocable life insurance trust or by an adult beneficiary from the outset — a structuring decision to take with an estate lawyer before the policy is issued, since transferring an existing policy starts a three-year lookback.
DIME against the other ways of sizing coverage
Three other methods are in common use, and each trades accuracy for simplicity differently.
The income multiple rule says buy ten to twelve times gross income. It is fast, it is roughly right for a household with an average mortgage and one or two children, and it has no way to be wrong in a specific direction — it simply ignores your balance sheet. It underestimates for anyone with a large mortgage or several children and overestimates for a household with no dependants and no debt.
The human life value method computes the present value of your entire remaining lifetime earnings net of your own consumption and taxes. It is the most theoretically defensible and it is what a court uses in a wrongful death claim, but it usually produces a number far larger than a household will pay for, and it is sensitive to assumptions about career progression that nobody can support.
The capital needs or capital retention method asks what lump sum would generate the required income in perpetuity without being consumed — annual need ÷ real rate. At $59,500 and 2% real that is $2,975,000, more than double the DIME answer, because it never spends the principal. It is the right method when the goal is to leave an endowment rather than to bridge a period.
DIME sits between them: it consumes the principal like a bridge, it uses balance-sheet items you can verify, and it produces a number households actually buy. Use it as the working figure, sanity-check it against the income multiple, and if the two disagree by more than about 30% find out which of your inputs is driving the difference before you sign anything.
One last comparison worth making explicitly. Whatever face amount you settle on, the product decision follows: level term for a defined, declining need, or permanent cover for an estate or a lifelong dependant. The premium difference is large and persistent, and the term vs whole life cost comparison calculator quantifies it over the period you actually intend to hold the policy.