How Lenders Calculate Your Mortgage Qualifying Income: Salary, Hourly, Overtime/Bonus Explained
Income Basics: How Lenders Calculate Your Qualifying Income for a Mortgage Part One
Over the past few weeks, we’ve talked about credit, liabilities, debt-to-income, and assets.
Now, we’re moving into one of the most important, and often confusing, parts of getting a mortgage: income calculation.
This topic is big, so I’m breaking it into several articles. We’ll cover all types of income—full-time, part-time, self-employed, gig work, and passive income—and what underwriters look for with each one. My goal is to explain how lenders determine qualifying income in a way that makes sense, without the jargon.
Let’s start with the most common: a full-time job.
Gross vs. Net Income for a Mortgage
When you apply for a home loan, the lender starts with gross income (the amount you earn before taxes), Social Security, insurance, retirement contributions, or other deductions.
Your qualifying income for a mortgage is based on this gross amount, calculated into a monthly figure.
Salary Income: The Easiest to Calculate
If you’re on a salary, your pay stays the same every payday. You might be paid weekly, every two weeks, twice a month, or monthly.
Here’s how to figure out your monthly gross income for mortgage purposes:
Annual salary ÷ 12
Example: $85,000 ÷ 12 = $7,083.33 per month
Paid every two weeks (bi-weekly): gross paycheck × 26 ÷ 12
Example: $1,000 × 26 ÷ 12 = $2,166.67 per month
Paid twice a month (semi-monthly): gross paycheck × 24 ÷ 12
Example: $1,000 × 24 ÷ 12 = $2,000 per month
Paid monthly: use your gross monthly pay—no calculation needed.
Salary math is simple. Hourly pay? That’s where it gets tricky.
Hourly Pay: Fluctuating Income and Averages
If you’re paid hourly, your weekly hours might not be the same, 38 one week, 40 the next, maybe 42 with overtime. This is called fluctuating income, and lenders must average it to figure out your qualifying income.
Example:
Gary earns $32 an hour and works 40 hours a week.
Weekly math:
$32 × 40 = $1,280 per week
$1,280 × 52 weeks = $66,560 annually
$66,560 ÷ 12 months = $5,546.67 per month
Check against year-to-date (YTD) income:
If Gary’s YTD pay is $33,280.02 as of June 30:
$33,280.02 ÷ 6 months = $5,546.67 per month
If the numbers match, that’s the income used. If not, the underwriter will ask why. Maybe it’s a raise, fewer hours, or normal scheduling differences.
When Lenders Average Your Income
If hours vary, the lender might average your income over the last 12 to 24 months.
Example:
Gary earned $64,300 in 2024 and $30,500 in the first half of 2025:
$64,300 + $30,500 = $94,800 over 18 months
$94,800 ÷ 18 = $5,266.67 per month
That $280 difference from the earlier figure could impact how much he qualifies to borrow.
Mortgage Lending Explained is a reader-supported publication. To receive new posts and support my work, consider becoming a free or paid subscriber.
Overtime and Bonus Income for a Mortgage
If you get overtime or bonuses, most lenders want to see at least two years of history before they’ll count this income toward your qualifying amount. Bonus income is calculated the same way as overtime.
Example:
2023: $2,500 overtime
2024: $2,600 overtime
2025 YTD (through June): $1,500 overtime
Step 1: Add them together:
$2,500 + $2,600 + $1,500 = $6,600 over 30 months
$6,600 ÷ 30 = $220 per month overtime income
Step 2: Check if it’s consistent this year:
$1,500 ÷ 6 months = $250 per month. Yes, consistent.
Some lenders are more conservative and only average the past two full years, which could lower the qualifying amount.
Why Your Qualifying Income Can Vary by Lender
Mortgage income calculations aren’t always identical from lender to lender. Loan program rules can differ, and guidelines change over time.
The best way to avoid surprises is to give your lender all your income documents upfront (paystubs, W-2s, and any other proof of earnings) and let them do the math.
If the number seems off, ask them to walk you through it. You have every right to know how they got there.
Final Thoughts and an Invitation
When you apply for a mortgage, lenders will add up all your eligible income sources to find your total qualifying income. This number helps you determine how much house you can afford, but keep in mind that it may not match what’s shown on your pay stub or tax return.
Figuring out your qualifying income for a home loan can be frustrating, even for underwriters. But it’s one of the most essential steps in the mortgage process.
Have you tried calculating your income and found the lender’s number was different? Higher? Lower?
Drop me a message and let’s talk it through. I’m here to explain the rules, run the numbers, and help you feel confident before you take the next step toward your home purchase.
