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Michael Lip
Michael Lip

Posted on • Originally published at zovo.one

FHA Loans Explained: The Math Behind the 3.5% Down Payment

When I first looked at buying a home, every conventional loan calculator told me I needed 20% down. On a $350,000 house, that is $70,000. For a lot of first-time buyers, that number might as well be a million. Then someone mentioned FHA loans, and the math changed entirely.

An FHA loan is a mortgage insured by the Federal Housing Administration. The key difference is the down payment: 3.5% instead of the conventional 20%. On that same $350,000 house, your down payment drops to $12,250. The trade-off is that you pay mortgage insurance premiums, and understanding that trade-off is where most people get confused.

How FHA mortgage insurance works

FHA loans require two types of mortgage insurance:

Upfront Mortgage Insurance Premium (UFMIP): 1.75% of the loan amount, paid at closing. On a $337,750 loan (that $350,000 house minus 3.5% down), that is $5,910. Most borrowers roll this into the loan balance rather than paying it in cash.

Annual Mortgage Insurance Premium (MIP): 0.55% of the loan balance per year for most borrowers, divided into monthly payments. On a $337,750 loan, that is roughly $155 per month initially, decreasing as you pay down the principal.

Here is where it gets important: for FHA loans with less than 10% down, MIP lasts for the life of the loan. You cannot cancel it like you can with conventional PMI once you hit 80% loan-to-value. The only way to eliminate it is to refinance into a conventional loan once you have enough equity.

Running the real numbers

Let me walk through a concrete comparison. Assume a $350,000 home purchase with a 6.5% interest rate over 30 years.

FHA loan (3.5% down):

  • Down payment: $12,250
  • Loan amount: $337,750 + $5,910 UFMIP = $343,660
  • Monthly principal and interest: $2,173
  • Monthly MIP: ~$155
  • Total monthly payment (P&I + MIP): $2,328

Conventional loan (20% down):

  • Down payment: $70,000
  • Loan amount: $280,000
  • Monthly principal and interest: $1,770
  • Monthly PMI: $0
  • Total monthly payment: $1,770

Conventional loan (5% down):

  • Down payment: $17,500
  • Loan amount: $332,500
  • Monthly principal and interest: $2,102
  • Monthly PMI: ~$166 (until 80% LTV)
  • Total monthly payment: $2,268

The FHA payment is higher than the 5% conventional, but the FHA credit requirements are significantly more forgiving. FHA accepts credit scores down to 580 for the 3.5% down option, while conventional loans typically want 620 or higher and reserve the best rates for 740+.

When FHA makes sense

FHA loans are not universally better or worse than conventional loans. They solve a specific problem: getting into a home when you have limited savings or imperfect credit.

FHA makes sense when:

  • Your credit score is between 580 and 680 and conventional rates would be significantly higher
  • You have 3.5-10% for a down payment but not 20%
  • You want to buy sooner rather than saving for years to hit 20%
  • The home price is below the FHA loan limit for your county

FHA does not make sense when:

  • You have 20% down and good credit (go conventional, skip insurance entirely)
  • You have 10-15% down and excellent credit (conventional PMI will be cheaper and cancellable)
  • You are buying a home above FHA limits ($498,257 in most areas, up to $1,149,825 in high-cost counties for 2024)

The refinancing strategy

Many savvy buyers use FHA as a stepping stone. Buy with 3.5% down using FHA. Make payments for a few years while the home appreciates. Once you have 20% equity, refinance into a conventional loan and eliminate mortgage insurance entirely.

This strategy depends on home values not declining and interest rates being favorable when you refinance. It is not guaranteed, but historically it has worked for most markets over 3-5 year holding periods.

The break-even calculation

The question most buyers should ask is: does paying MIP cost me more or less than waiting to save a larger down payment?

If you are paying $1,500 per month in rent and it would take you three years to save from 3.5% to 20%, that is $54,000 in rent with zero equity. Meanwhile, home prices might appreciate 3-5% annually. On a $350,000 home, that is $10,500-$17,500 per year in appreciation you miss out on.

The MIP over those three years would cost roughly $5,400. In most scenarios, buying now with FHA beats waiting, but the specifics depend on your local market and rent situation.

I built an FHA loan calculator at zovo.one/free-tools/fha-loan-calculator that models the full cost including UFMIP, annual MIP, and comparison against conventional loan options. Plug in your numbers and see exactly what the monthly payment looks like with all the insurance costs included.


I'm Michael Lip. I build free developer tools at zovo.one. 500+ tools, all private, all free.

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