Why I built RealAfford
I created RealAfford because I was a first-time homebuyer who couldn't find a calculator that answered my real question: "After I pay my mortgage, taxes, insurance, groceries, and other obligations, what will I actually have left to live on?"
Every calculator I found told me what the bank would approve me for. But approval isn't the same as affordability. Banks don't care if you can still afford groceries, grow your savings, or go on vacation. They just want to know if you'll make your payments.
I wanted tools that would help me understand the full picture. Not just whether I could get a loan, but whether I could comfortably live in the home I was buying, and whether buying even made sense compared to renting.
So I built them.
Our calculators
RealAfford offers two free calculators, each designed to answer a different question:
Home Affordability Calculator
The question it answers: "If I buy this home, what will I actually have left to live on each month?"
We use take-home pay, not gross income
The traditional "28/36 rule" uses your pre-tax income, but you don't spend pre-tax dollars. You spend what hits your bank account. We ask for your actual take-home pay because it's more accurate and actionable.
We account for regional cost of living
$3,000 left over in Mississippi goes a lot further than $3,000 in California. When you enter your ZIP code, we adjust our estimates for groceries, transportation, and other essentials based on your state's cost of living index.
We show you what's actually left
After subtracting your housing costs, debts, utilities, and maintenance, we estimate your remaining monthly budget. Then we compare that against typical living expenses for your household size to tell you whether you'll be comfortable, stretched thin, or house broke.
We estimate your interest rate based on credit score
Your credit score significantly impacts your mortgage rate. Instead of guessing, we estimate your likely rate based on your credit score range and loan term. Higher scores get better rates, and shorter loan terms typically offer lower rates. You can always adjust if you have an actual lender quote.
Try the Affordability CalculatorRent vs Buy Calculator
The question it answers: "Over the next X years, will I be better off financially if I rent or buy?"
We factor in opportunity cost
If you rent, you keep your down payment money. We calculate what that money could grow to if invested in the stock market instead of being tied up in a house. This is often the biggest factor in the rent vs buy decision, yet most calculators ignore it.
We use current tax law
The 2017 tax changes mean most homeowners no longer get a tax break from their mortgage. We calculate whether you'd actually benefit from itemizing based on your income and home price, using the current standard deduction ($14,600 single / $29,200 married).
We show you the break-even point
Our timeline visualization shows exactly when buying becomes cheaper than renting. If you might move before that point, renting could save you money.
We include all the hidden costs
Closing costs when you buy (2-5%), selling costs when you move (7-10% for agents and fees), maintenance (1% of home value annually), property taxes, insurance, HOA fees, and extra utilities. These add up fast and can completely change the math.
We show results in today's dollars
All figures are adjusted for inflation so you can make apples-to-apples comparisons across different time horizons. A dollar 10 years from now won't buy as much as a dollar today.
We test different scenarios
Our sensitivity analysis shows how your outcome changes under different assumptions. What if home prices grow faster or slower? What if the stock market does better or worse? See how robust your decision is.
Try the Rent vs Buy CalculatorThe numbers we use
Property tax rates are state averages from tax assessment data, ranging from 0.28% (Hawaii) to 2.49% (New Jersey).
PMI estimates are calculated based on loan-to-value ratio:
- LTV 80-85%: ~0.375% annually
- LTV 85-90%: ~0.625% annually
- LTV 90-95%: ~0.875% annually
- LTV 95%+: ~1.03% annually
Cost of living adjustments are based on regional price parity data, normalized to a national average of 100.
Interest rate estimates are based on credit score and loan term:
- Excellent (760+): Base rate
- Very Good (720-759): +0.25%
- Good (680-719): +0.50%
- Fair (640-679): +1.00%
- Poor (600-639): +1.75%
- Very Poor (<600): +2.50%
Shorter loan terms also affect rates: 15-year loans are typically ~0.7% lower than 30-year loans.
Affordability thresholds for take-home pay:
- Comfortable: Housing costs under 35% of take-home
- Stretching: Housing costs 35-50% of take-home
- Aggressive: Housing costs over 50% of take-home
Important: RealAfford provides estimates for educational purposes. Your actual costs will vary based on your lifestyle, location within your state, health needs, and spending habits. This is not financial advice. It's a starting point for making informed decisions.
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