The "how much" question has a defensible answer, but most published advice answers a different question. The 20-times-salary rule of thumb is the worst offender: it produces a number with no derivation behind it, and for most households it overshoots the actual need by a factor of two or three. The honest approach is to enumerate every future obligation your family will face, discount each one to today's dollars, and subtract everything else that will cover it. That is the needs method, and it is worth doing by hand once.
Needs analysis: the method that actually works
The formula is a subtraction, and every term in it is something you can look up:
Coverage needed = PV(future obligations) − (existing assets + other insurance + government benefits)
Three steps, in order. First list the obligations that die with you: the mortgage balance, the children's education, the income your household needs for a number of years. Second convert each to a present value, because a $25,000 tuition bill in four years is not a $25,000 liability today. Third subtract the resources that will already be there — savings, retirement accounts, the existing life insurance, the group policy from work, and any government benefit. The life insurance needs calculator does exactly this sequence and shows the intermediate lines, which is the part people usually want to see.
The discounting step is where most back-of-envelope versions go wrong. Future spending is not the same as money spent today, and an obligation ten years out is only as large as its present value. A useful mental rule: to find today's value of a future amount, divide by 1.05 raised to the number of years out. At 5% a year, tuition four years out is roughly 82% of its face amount, and a ten-year income-replacement stream is well under half its undiscounted total.
Worked example: a household with a mortgage, two kids, and one income
Let us size coverage for a specific family. All figures are illustrative, in dollars:
- Household income: $80,000 per year, from one earner
- Mortgage balance remaining: $320,000
- Education: two children, four years each at $25,000 per year = $100,000
- Living expenses to cover: $40,000 per year for 10 years = $400,000
Adding the obligations undiscounted, the gross need is 320,000 + 100,000 + 400,000 = $820,000. This is the conservative starting point that most needs calculators present, and it is deliberately an over-estimate because it ignores discounting.
Now the offsets. This household has $150,000 in savings, $100,000 of employer-provided group life, and $50,000 of Social Security survivor benefit. Total offsets: $300,000. Net need: 820,000 − 300,000 = $520,000.
Round to a clean $600,000 of coverage, which is 7.5 times income. Note how that compares to the two shortcuts it beats: the 5-times-income sanity check says $400,000, and the 20-times rule says $1,600,000. The itemised answer sits between them and much closer to the disciplined one.
Here is a criticism worth making of that $520,000, because the offsets are the soft part of any needs analysis. $100,000 of group life is generous — employer cover commonly runs one to two times salary with a cap, and it disappears the day the job does, which for a mortgage with 18 years left is exactly the wrong time. $50,000 of Social Security is also generous: survivor benefits pay only a spouse and minor children, never an unmarried partner, and the payment replaces a minority of income rather than all of it. Strip both to conservative values and the net need rises above $650,000. The honest summary is that $600,000 is defensible for this family, and so is $650,000 — the method matters far more than the final digit, which is why the debt to income calculator is a useful cross-check on whether the premium is affordable alongside the mortgage.
DIME: faster, rougher, and better than nothing
DIME is an acronym for four buckets, and it takes about two minutes:
- D — Debt: everything you owe, including the mortgage. For our family that is $320,000.
- I — Income: the yearly income your household needs, multiplied by the number of years it is needed. This is the bucket people most often inflate.
- M — Mortgage: the repayment obligation. Note this is a trap — the mortgage is already counted under Debt, and counting it again as a separate need is the most common DIME error, double-counting tens of thousands of dollars.
- E — Education: the projected cost of raising children to independence. $100,000 here.
Set up properly with the mortgage counted once, DIME lands in the same region as needs analysis. Set up with the mortgage counted twice, it overshoots. The method is a reasonable screening tool; the needs analysis is the one to use when the answer is going to determine a purchase you will pay for two decades.
Income replacement: the sound idea inside the bad rule
The reasoning behind 20 times salary is not crazy. If a family needs $80,000 a year for 20 years, that is $1.6 million of future spending, and someone might reasonably think "I need $1.6M of insurance." The problem is that the rule skips three corrections that the arithmetic demands.
Discounting. $80,000 spread over 20 years is not $1.6M of today's dollars. At 5%, the present value of a $40,000-a-year stream for 20 years is roughly $455,000, not $800,000 — the distant years count for much less. The mortgage calculation guide covers the same annuity logic that makes discounting work.
Double-counting. Income replacement computed alongside a mortgage and education budget counts the same money twice. A mortgage is a debt, not income replacement; education is not income replacement. Once those are separately accounted for, the remaining income-replacement need is far smaller.
The "full income" assumption. Many families have two incomes, or a working partner, or a spouse who can re-enter the workforce. Replacing one full income for two full decades rarely matches the actual cash gap.
Three to five times income is a defensible sanity check precisely because it is a rough one. The salary calculator will give you the exact income figure to multiply, and the debt to income ratio guide explains why lenders and insurers care about the same ratio from opposite directions.
Estate tax, stated carefully
One obligation is real but rarely binding, and it is the one most often oversold. The US federal estate tax exemption has been around $13 million per person and is indexed upward for inflation — 2025's figure was roughly $13.61 million, and it changes most years. Portability allows a surviving spouse to use the unused exemption, so couples can effectively shelter a very large estate between them. Non-resident aliens get a much lower exemption, around $13,000, which catches cross-border families, and a handful of states impose their own estate or inheritance tax with far lower thresholds. All of this changes: treat these as order-of-magnitude figures and check the current IRS figures and your state law before relying on any of them.
The practical read: for most families the estate tax is not a reason to buy life insurance, because the assets do not exceed the exemption. It becomes a reason only when a state estate tax applies, when a non-resident-alien rule bites, when a business interest is involved, or when the goal is a bequest to heirs and charity rather than tax avoidance. The tax brackets guide is worth reading alongside this, because an income-tax bracket is the more likely leak in most families' finances.
What actually moves the premium
Once the amount is set, the price is a function of age, health, term length, and coverage amount. Age is the dominant variable, and the progression is steep enough to be worth planning around. As a rough illustration for a healthy non-smoking male on a 20-year term, $100,000 of coverage runs about $90 a year at age 30 and about $400 a year at age 50 — a bit over four times the cost for the same protection. Actual rates depend on carrier, health class, tobacco use, and the underwriting year, and this is a magnitude reference rather than a quotation.
That four-fold difference is the strongest argument for buying early. Coverage bought in your 30s is the cheapest coverage you will ever obtain, and locking in a large amount while healthy is one of the few financial decisions whose cost does not rise with time. It also explains why the needs analysis is usually a one-time exercise: solve it once, buy the gap as term, and re-check when a major change occurs — a marriage, a birth, a home purchase, a job change.
For the family above, $600,000 of 20-year term at roughly $0.90 per $1,000 per year for a healthy 35-year-old works out to about $540 a year. Set against an $80,000 income that is under one percent, which is the point: adequate coverage is cheap, and under-insuring is the expensive mistake.
Recheck triggers
Run the analysis again when any of these change: a new dependent, a marriage or divorce, a home purchase or a mortgage payoff, a promotion or a career change that alters income, a business interest that creates a buy-sell obligation, or a policy anniversary. The term life insurance calculator makes it easy to price the new scenario, and comparing it against the term versus whole life guide is the right next step if you are also weighing a permanent policy.
Frequently asked questions
What is the difference between needs analysis and DIME?
Needs analysis lists each specific future obligation and discounts it to today's dollars, then subtracts what other resources already cover. DIME is an acronym — Debt, Income, Mortgage, Education — that bundles those obligations into four numbers. Needs analysis is the more thorough method; DIME is faster and easier to run, so it usually produces a smaller, rougher answer.
Is 20 times salary a good rule for life insurance?
No, it is a marketing shortcut with no real logic behind it, and it usually overstates the need badly. The idea at its core — years of income replacement — is sound, but it ignores discounting, double-counts the mortgage and education, and assumes full income is replaced for twenty straight years.
Should I count Social Security and employer life insurance against my policy?
You can, but discount them. Employer group life is usually one to two times salary with a cap, and it disappears when the job does. Social Security survivor benefits only pay a spouse and minor children, never an unmarried partner, and replace only a minority of income. Counting them at full value is the most common way a needs analysis understates the gap.
Why does coverage cost so much more at 50 than at 30?
Because insurers price mortality by age, and it rises steeply later in life. A 50-year-old is roughly four times as likely to die over a 20-year term as a 30-year-old, so the premium per dollar of coverage is about four times higher. Locking in coverage in your 30s is the cheapest available moment.