Money numbers you need to know

Your doctor needs to know certain numbers to judge your physical health, such as your weight, your blood pressure and your cholesterol levels.

Similarly, you need to know certain numbers to monitor your own financial health, including:

After-tax income, must-have expenses

Your after-tax income is your gross income minus the taxes you pay. If you get a steady paycheck, you can use your latest pay stub to calculate this figure. Otherwise, check your most recent tax return.

Divide your after-tax income by the number of hours you worked to earn it. That gives you a rough idea of how much time you’re trading when you buy something. For example, if you make $20 an hour after tax and something costs $100, you have to work five hours to afford it.

Your after-tax income also is the basis for the 50/30/20 budget, a spending plan that helps you balance current expenses, debt payments and savings. That budget suggests limiting your essential or must-have expenses — shelter, utilities, transportation, food, insurance, minimum loan payments and child care needed to work — to 50% of after-tax income. Wants, such as vacations and dining out, make up 30%. That leaves

20% for savings and extra debt payments.

Lifetime income and net worth

You can access your Social Security statement, including your lifetime earnings history, by signing up at socialsecurity.gov/myaccount. Add up your annual earnings, plus any other income you’ve received such as gifts, inheritances, investment income, pensions, under-the-table earnings or government benefits. (Estimates are fine.)

Now, calculate your net worth by subtracting what you owe (your debts, including loans, credit card debts and mortgages) from what you own (your assets, such as your home, retirement accounts, investments and savings).

Full retirement age and expected Social Security benefit

Your full retirement age is the age at which you are entitled to 100% of the Social Security benefits you’ve earned. If you apply for benefits before that age, your checks will be permanently reduced. If you delay your application until after full retirement age, you can qualify for delayed retirement credits that boost your benefit by 8% each year until 70 years old, when benefits max out.

For those born 1943 through 1954, your full retirement age was 66. After that, full retirement age increases by two months each year: it’s 66 and two months for people born in 1955; 66 and four months for people born in 1956, and so on. The full retirement age is 67 for people born in 1960 and later.

You’ll find estimated benefits in your Social Security statement.

Retirement savings rate

How much of your income are you saving for retirement? Is your savings plan likely to let you retire when you want? An online retirement calculator can give you a ballpark figure.

Credit scores and debt-to-income ratio

Monitoring at least one of your credit scores can allow you to see your progress in building credit and alert you to problems, such as identity theft.

To calculate your debt-toincome ratio, combine your monthly debt payments with your current rent or mortgage payment and compare that with your monthly income. A debt-to-income ratio of 36% or less is considered good by most lenders. A ratio over 50% could make it difficult to get approved for new loans.