The old rule of thumb — ten times your salary — is a starting line, not a finish line. The real number is a function of who depends on your income, what debts you leave behind, and which milestones you want funded even if you're not there to fund them.
Start with income replacement. Multiply your annual income by the number of years your dependents would need it — typically until the youngest is self-sufficient or a spouse can rebuild. For most working families that lands between 10 and 15 times annual income, but the exact multiple depends on existing savings and a surviving spouse's earning capacity.
Next, add your liabilities. A mortgage, business loans, and any co-signed debt should be covered so they don't become a burden on the people you intended to protect. Then layer in future obligations you wanted to fund: college tuition, a spouse's retirement cushion, an emergency reserve. These are the goals that disappear if your income does.
Finally, subtract what you already have — savings, investments, and any employer-provided coverage. What remains is the gap a policy should fill. The point is to right-size the benefit: too little leaves your family exposed, too much drains cash you could be putting to work elsewhere. A needs-based calculation beats a rule of thumb every time.