
Most buyers start with a mortgage calculator and a price they saw online, then work backward. The problem is that a calculator only shows you the principal and interest — it misses the costs that vary wildly between New Jersey and Florida. Property taxes, insurance, HOA fees, and flood insurance can change your real monthly payment by hundreds of dollars. Here is how to build a budget that reflects what you will actually pay.
Start With the 28/36 Rule
The 28/36 rule is a time-tested guideline lenders use as a starting point:
- 28% (front-end): Your total housing payment — principal, interest, property taxes, insurance, and HOA — should stay under 28% of your gross monthly income.
- 36% (back-end): All of your debt payments — housing plus car loans, student loans, credit cards — should stay under 36% of your gross monthly income.
On a $100,000 income, that means a housing payment up to about $2,333/month and total debt up to $3,000/month. But because New Jersey taxes and Florida insurance are high, many buyers find their comfort zone is closer to 25% or lower. Use 28% as a ceiling, not a target.
Understand DTI (Debt-to-Income Ratio)
DTI is the number lenders actually use to decide how much to lend you. It is your monthly debt payments divided by your gross monthly income.
- Conventional loans: Cap back-end DTI around 45%.
- FHA loans: Cap around 43–50% with strong compensating factors.
- VA loans: Cap around 41% (with some flexibility).
A lower DTI gives you more purchasing power and a stronger approval. Paying down a car loan or credit card balance before applying can meaningfully increase the loan amount you qualify for.
The NJ vs FL Cost Difference
This is where affordability diverges most between the two states. The same monthly payment buys very different homes depending on where you buy.
- Property taxes: New Jersey has the highest in the country — often $8,000–$12,000+ per year on a median home. Florida's are a fraction of that, but the homestead cap only applies after you own and occupy. Learn more in our NJ vs FL property tax comparison.
- Insurance: Florida insurance can run $3,000–$8,000+ per year, especially near the coast, and flood insurance is separate. New Jersey insurance is generally lower but still significant. See our Florida insurance and wind mitigation guide.
- HOA: Common in Florida condos and planned communities, sometimes $300–$700/month. Factor this into your housing payment.
Because these costs are escrowed into your monthly payment, a high tax or insurance bill directly reduces the loan amount you can qualify for. Always include them in your budget, not just the mortgage.
A Simple Affordability Worksheet
- Calculate your gross monthly income (before taxes). For couples, combine both incomes.
- List all monthly debt payments: car, student loans, credit card minimums, child support.
- Multiply your gross monthly income by 0.28 to find your target housing payment ceiling.
- Subtract estimated monthly property taxes and insurance from that ceiling — what is left is for principal and interest.
- Use a mortgage calculator to translate that principal-and-interest amount into a loan size at the current rate.
- Add your down payment to that loan size to get your target purchase price.
How to Increase What You Can Afford
- Pay down debt to lower your DTI — this is the fastest lever.
- Improve your credit score to qualify for a lower interest rate, which increases your purchasing power.
- Save a larger down payment to reduce the loan amount. See how much down payment you need.
- In Florida, shop insurance early and consider homes outside high-risk wind or flood zones to lower premiums.
- In New Jersey, budget for taxes up front so you do not overbuy.
Use Real Numbers, Not Estimates
The best way to know what you can afford is to get pre-approved. A pre-approval gives you a real loan amount based on your actual income, debt, and credit — not a guess. Pair it with our mortgage calculator to see how different prices, rates, and down payments change your monthly payment. When you are ready, schedule a conversation with Christian to build a buying plan that fits your budget and your goals.
Related Reading for NJ and FL Buyers
For more, read about down payment requirements, buyer closing costs, or getting pre-approved.

Christian Tibok
REALTOR serving homeowners across New Jersey and Florida. Christian helps buyers build realistic budgets that account for local taxes, insurance, and closing costs. Learn more about Christian.
