Life Insurance Basics: How Much You Need and What It Costs
How to size a life insurance policy with the DIME method, who actually needs cover, what delay costs, and how to buy without overpaying.
Table of contents
Life insurance is one of the few financial products people buy without any idea what the right amount is.
Ask most policyholders why they hold $250,000 rather than $600,000 and the honest answer is that it was the number on the form, or roughly what the payment felt affordable at. That’s how people end up either badly underinsured or paying for cover nobody needs.
Here’s how to work out the amount, whether you need it at all, and what it should cost.
Do you actually need it?
Worth answering first, because a meaningful number of people who buy life insurance shouldn’t have.
Life insurance replaces income for people who depend on it. That’s the whole function. If nobody is financially exposed by your death, there’s nothing for a policy to do.
The most common misplaced fear is leaving debts behind. Most unsecured debt (credit cards, personal loans, medical bills) dies with the estate. It doesn’t transfer to your family unless they co-signed or live in a community property state where specific rules apply. Federal student loans are discharged on death. Private student loans sometimes aren’t, which is one of the few genuine exceptions worth checking.
The clearest cases for cover are a partner who couldn’t carry the mortgage alone, children who’d need raising, and any debt someone else signed for.
Sizing the policy
DIME is rough, and rough is fine. What matters is producing a figure you can defend rather than accepting whichever number an application form defaults to.
Worked example: a full DIME calculation
A 36-year-old earning $82,000, married with two children aged 4 and 7. Partner works part-time earning $24,000.
| Component | Working | Amount |
|---|---|---|
| Debt | Car loan $14,000, cards $6,000 | $20,000 |
| Income | $82,000 × 16 years (until youngest is 20) | $1,312,000 |
| Mortgage | Outstanding balance | $268,000 |
| Education | 2 × $115,000 | $230,000 |
| Subtotal | $1,830,000 | |
| Less employer cover (2× salary) | −$164,000 | |
| Less savings and investments | −$96,000 | |
| Cover needed | $1,570,000 |
Most people’s instinct before running this is somewhere around $500,000. The gap between instinct and arithmetic is the entire reason to do the exercise.
A word on that employer line. It’s subtracted here because it exists today, but it disappears the day the job does, which is frequently the same period the family is under most strain. If you’d rather be conservative, leave it out of the subtraction entirely and treat it as a buffer.
Worked example: what the “years” assumption does
The income component dominates the total, and it hinges on one judgement call.
| Years of income replaced | Income component | Total cover needed |
|---|---|---|
| 10 | $820,000 | $1,078,000 |
| 16 (to youngest turning 20) | $1,312,000 | $1,570,000 |
| 25 (to retirement age) | $2,050,000 | $2,308,000 |
A $1.2 million swing on one assumption. The usual anchor is “until the youngest finishes education,” because that’s when the dependency genuinely ends. Replacing income to your own retirement age overinsures for most families, since the surviving partner typically returns to fuller earnings.
What it costs
Term life is cheaper than almost everyone expects, and the surprise runs in the useful direction.
For a healthy 35-year-old non-smoker, a 20-year term policy with a $500,000 benefit commonly sits around $30 to $45 a month. That’s less than most phone bills, for the thing standing between your family and losing the house.
Worked example: what waiting costs
Same person, same $750,000 policy, 20-year term. Only the age at purchase changes.
| Age at purchase | Monthly premium | 20-year total |
|---|---|---|
| 30 | $41 | $9,840 |
| 35 | $54 | $12,960 |
| 40 | $82 | $19,680 |
| 45 | $137 | $32,880 |
| 50 | $228 | $54,720 |
Waiting from 30 to 40 costs roughly $9,840 more over the life of the policy, for identical cover. Waiting to 50 more than quintuples it.
And that assumes your health stays as it is. It’s the second variable, and unlike age it can move suddenly. A diagnosis between 35 and 40 doesn’t just raise the price, it can remove the option entirely. This is the strongest argument in the whole subject: buy it while you’re healthy, because health is the one input you can’t get back.
Term or permanent
Briefly here, because it deserves its own treatment and has one: our term vs whole life comparison works through the full trade-off with cost figures.
The short version. Term covers a set period, has no cash value, and is dramatically cheaper. Permanent covers your whole life, builds cash value, and costs five to fifteen times more for the same death benefit.
For the job most people are buying life insurance to do (replacing income while children grow up and a mortgage gets paid down) term does it better and far more cheaply. The need genuinely expires, so cover that expires with it is the right shape.
Permanent cover solves different problems: estate liquidity, a lifelong dependant, business continuity. Real problems, but not the ones most families have.
Buying it in the right order
Two of those deserve expansion.
Be completely honest on the application. Insurers verify with medical records, prescription databases and sometimes a paramedical exam. Understating tobacco use or omitting a condition doesn’t usually get caught at application. It gets caught during the two-year contestability period, when a claim is investigated, and that’s the worst possible moment for it to surface.
Worked example: what a misstatement costs
Someone declares non-smoker while smoking occasionally, saving $61 a month on a $600,000 policy.
| Honest application | Misstated | |
|---|---|---|
| Monthly premium | $118 | $57 |
| Saved over 3 years | — | $2,196 |
| Death within contestability period | $600,000 paid | Claim investigated, likely denied |
| Outcome for the family | Mortgage cleared | Premiums refunded, cover gone |
Two thousand dollars saved against a $600,000 risk of the policy not working. There is no version of that trade that makes sense.
Check for conversion options. A convertible term policy lets you switch to permanent cover later without new medical underwriting. It usually costs little or nothing extra and preserves an option you may want if your circumstances change or your health does. It’s the single most underrated feature in a term policy.
Common mistakes
Relying only on employer cover. Typically one to two times salary, against a need closer to ten. And it ends with the job.
Insuring only the earner. A stay-at-home parent’s work has real replacement cost. Childcare, household management and the earning capacity the surviving partner loses while covering both roles. $250,000 to $400,000 of cover on a non-earning parent is not unusual and is frequently overlooked.
Buying decreasing-term mortgage cover by default. It’s cheap because the benefit falls as the mortgage does. Level term at the full DIME figure covers the mortgage and everything else, often for a similar premium.
Naming the estate as beneficiary. Proceeds then go through probate, which delays payment and can expose them to creditors. Name people directly, and review beneficiaries after any marriage, divorce or birth. This is the most common administrative error in the whole product.
Buying once and never revisiting. A policy sized at the birth of your first child is wrong by the third. Review every three to five years, and after any major life change.
Getting started
Run the numbers first. Our life insurance need calculator does the DIME arithmetic, and our guide to using insurance calculators covers testing how sensitive the answer is to the years assumption.
Then get quotes from three insurers at that figure and term. Check each carrier’s complaint index and financial strength using the approach in our comparison guide — with life insurance the payout may be forty years away, so the company’s durability matters more here than in any other line.
The medical exam, and how to prepare for it
Most fully underwritten policies involve a paramedical exam, and small preparation choices move the rating band, which moves the premium for the whole term.
Schedule it for the morning, and fast beforehand if the insurer permits. Cholesterol and glucose readings are meaningfully better fasted.
Avoid alcohol for at least 48 hours and heavy exercise for 24. Both affect liver enzymes and can produce a reading that looks like a problem.
Skip caffeine and nicotine that morning. Both raise blood pressure, and blood pressure is a rating factor with real thresholds.
Sleep properly the night before, and be honest on the questionnaire. The exam and the medical records check will surface most things, and a discrepancy between what you declared and what the records show is treated as misrepresentation, which is far worse than the underlying condition.
Have your medications and doctors’ details written down rather than recalled from memory.
Worked example: the value of one rating band
A 40-year-old buying $750,000 of 20-year term.
| Rating | Indicative annual premium | Paid over 20 years |
|---|---|---|
| Preferred Plus | $640 | $12,800 |
| Preferred | $810 | $16,200 |
| Standard Plus | $1,020 | $20,400 |
| Standard | $1,280 | $25,600 |
One band is worth several thousand dollars across the term, and the gap between Preferred Plus and Standard is nearly double.
Two further notes. No-exam policies exist and are convenient, but they generally cost more for the same benefit because the insurer prices for the uncertainty. And if you are declined or rated worse than expected, the decision is not universal: underwriting appetite varies enormously between insurers, and a broker who places impaired risk regularly can often improve on it.
Reviewing cover as life changes
A life insurance need is not fixed, and the policy should be revisited at the points where it moves.
A new mortgage raises the need by roughly the balance. A child raises it substantially and extends the period. A partner leaving work raises it. A divorce changes both the amount and, critically, the beneficiary. A business partnership creates a separate need entirely.
Downward moves matter too. A mortgage paid off, children becoming independent and substantial savings accumulating all reduce the need, and a ladder of policies is designed to expire in step with that.
Two administrative habits carry most of the value. Review the beneficiary designation at every one of those events, because designations override wills and an out-of-date form is the most common way a policy pays the wrong person. And tell someone the policy exists, with the insurer and policy number written down somewhere your executor will find.
The most expensive mistake in life insurance is not buying the wrong product. It is buying the right one and having nobody claim it.
Three questions that follow immediately
The basics above cover what life insurance is and how the main products differ. Three questions come up next and each has a clear answer.
Is accidental death and dismemberment cover the same thing? No, and the difference matters more than anything else on this page. AD&D pays only for accidental death and specified injuries, and pays nothing for death from illness, which is how most people die. It is a reasonable cheap supplement, particularly when an employer provides it, and it is not a substitute at any price. Our guide to what AD&D insurance is sets out the schedule and the long exclusions list that make it inexpensive.
Can I insure a parent? Yes, subject to two absolute conditions: an insurable interest, meaning you would suffer financially from their death, and their consent, which is a legal requirement rather than a formality. Our guide to life insurance on your parents covers which product answers which need and how to structure ownership so the policy does what the family intended.
Who actually receives the money? Whoever the beneficiary designation names, which overrides a will. The most consequential and most neglected part of it is the contingent beneficiary, because without one the proceeds generally fall into the estate and into probate with it. Our guide to what a contingent beneficiary is covers the designation mistakes that recur and how to review every account that carries one in a single sitting.
The one thing to take away
If you have people who depend on your income and you don’t have cover, the cost of sorting it out goes up every single year, and one bad medical result can close the door entirely.
The arithmetic above takes twenty minutes. The application takes a few weeks. Doing it this month rather than next year is worth more than any amount of shopping around.
