The first time you sit down with an FHA quote and a conventional quote side by side, the numbers look almost like a clerical error. One lender offers 6.25%, the other 6.5%, and the monthly payments still land within a few hundred dollars of each other. The rate gap is real. The payment gap is being set somewhere else entirely, which is why running an FHA loan vs conventional loan calculator before you commit to either program is worth ten minutes of your evening.
A good calculator does one job well: it puts mortgage insurance on the same line as principal, interest, taxes, and homeowners insurance, so you can see what each loan actually costs per month and, more usefully, what it costs by year five, year ten, and year thirty. That last part is where most buyers get surprised.
Comparing the Two Programs on Rate Alone Hides the Real Cost
A 30-year FHA loan at 6.5% against a 30-year conventional loan at 6.25% reads like an easy win for conventional. Add the insurance layers and that win narrows, flips, or widens depending on four inputs: credit score, down payment size, loan amount, and how long you plan to keep the house.
The reason is structural. FHA mortgage insurance comes in two pieces, and one of them never goes away. Conventional mortgage insurance is one piece that expires on a schedule. Two loans with identical rates can differ by $400 a month five years in, purely because of how those insurance rules play out.
What the FHA Side of the Calculator Is Actually Computing
Upfront mortgage insurance premium (UFMIP). Charged at closing at 1.75% of the base loan amount, and usually financed rather than paid in cash. On a $386,000 base loan that adds $6,755 to your balance on day one, before a single payment is made.
Annual MIP. For most 30-year FHA loans with less than 5% down, this runs 0.55% of the loan amount per year, split across twelve payments. On $386,000 that’s $2,123 annually, or roughly $177 a month.
Duration. This is the detail that decides the whole comparison. With 3.5% down, FHA MIP lasts the full life of the loan. Refinancing into a conventional loan is the only exit. Put 10% down instead and the MIP falls off after eleven years, which changes the math considerably.
Credit flexibility. FHA’s floor is 580 for the 3.5% down program, or 500 with 10% down. Its pricing also punishes a 640 score far less than conventional lending does.
What the Conventional Side Is Computing
Private mortgage insurance. Required above 80% loan-to-value, priced by both credit score and LTV. A 740 score at 95% LTV might pay around 0.5% annually. A 660 score at the same LTV could pay closer to 1%, which is double the cost for the same loan.
Removal. PMI drops off automatically once your balance hits 78% of the original value, and most servicers will cancel it on request at 80%. On a standard amortization schedule that’s somewhere between year four and year eight depending on your down payment and whether you’ve paid extra principal.
Credit tiers. 620 is the typical floor, though 3% down programs like Fannie Mae HomeReady and Freddie Mac Home Possible stretch down to 620 with income limits. Below 620, conventional pricing gets ugly fast.
A $400,000 House, Both Programs, Same Buyer
Here’s how the comparison looks for a buyer with a 740 score putting down whatever each program allows:
- FHA, 3.5% down: $14,000 down, base loan $386,000, UFMIP financed to $392,755, 6.5% rate = $2,483 principal and interest plus $177 MIP = about $2,660 per month
- Conventional, 5% down: $20,000 down, loan $380,000, 6.25% rate = $2,340 principal and interest plus $158 PMI = about $2,498 per month
Conventional is cheaper by roughly $162 a month, but it requires $6,000 more at closing. Now fast-forward six years. Conventional’s PMI has disappeared, the payment drops to $2,340, and the monthly advantage over FHA doubles to more than $320. Over the full term, that original $162 gap becomes a six-figure difference.
Four Inputs That Flip the Winner
Credit score
Between 620 and 700, conventional’s pricing penalty can add half a point to a full point and a quarter to your rate. At that point the FHA quote stops looking expensive. Test it directly: a mortgage calculator by interest rate lets you see how much of your monthly payment is being decided by a 40-point FICO difference rather than by the loan program itself.
Down payment
Moving from 5% to 20% on a conventional loan eliminates PMI entirely. FHA charges MIP whether you put down 3.5% or 15%, so the marginal benefit of a bigger down payment is lopsided. Use a mortgage calculator with down payment to see what each additional 5% does to both the payment and the cash you’d need at the table.
Debt-to-income ratio
FHA is more forgiving here, often approving to 50% DTI through automated underwriting when there are compensating factors. Conventional typically caps near 45% to 50% depending on reserves and credit. If your DTI sits at 48% because of a car payment and a student loan, conventional may not approve you at all, and the comparison becomes academic. Check where you land with a housing expense ratio calculator before you get attached to either program.
How long you’ll keep the loan
FHA’s MIP never leaves. Conventional’s PMI does. Sell or refinance within three years and that difference barely registers, so FHA’s smaller cash requirement wins on flexibility alone. Stay ten years and the math tilts hard toward conventional.
Where FHA Genuinely Wins
Credit scores in the 580 to 660 range, thin credit files, a recent bankruptcy or foreclosure, high DTI with strong compensating factors, or a need for gift funds covering the entire down payment. FHA also allows seller concessions up to 6%, versus 3% on most conventional loans, which matters in a slow market where sellers are willing to negotiate.
Non-occupant co-borrowers are another FHA advantage. A parent can go on the loan to help with qualifying without living in the house, which is difficult or impossible under conventional guidelines.
Where Conventional Wins
Good credit, a down payment of 5% or more, and any intention of staying put. Conventional also avoids FHA’s property condition standards, which can sink a deal on a house with peeling paint, a shared well, or an aging roof. On a $400,000 purchase, a seller who has to fund repairs before closing often prefers a conventional buyer.
Loan limits matter too. FHA caps out lower than conforming conventional in most markets, so a larger purchase may only qualify for conventional financing. Run your income and debts through a mortgage qualification calculator to see which program’s ceiling you actually run into first.
The Break-Even Year Is the Number Worth Remembering
Run both loans and look for the month where cumulative cost crosses over. Add up everything: down payment, closing costs, UFMIP if you’re financing it, monthly insurance, and the point where conventional PMI drops off. For the example above, the crossover lands around year three or four. Before that, FHA’s lower cash-to-close leaves you ahead. After it, conventional pulls away and never looks back.
One thing that won’t help: recasting. A mortgage recast calculator will show you how a lump-sum principal payment lowers your monthly bill, but recasting doesn’t remove PMI any faster than scheduled payments do. If the goal is dropping mortgage insurance, extra principal payments do the job; a recast just re-spreads the balance you have left.
Run Both Calculations With the Down Payment Held Equal
The most common mistake is comparing FHA at 3.5% against conventional at 5% or 20%. That’s two variables changing at once, and it tells you nothing about which program is better for you. Set both calculators to the same down payment, say 5% on a $400,000 house, and the difference you see is pure program cost: mortgage insurance structure, rate adjustment, and fees.
Then run it a second time at each program’s minimum down payment to see what your actual cash-to-close looks like. If the lower-cash option wins on both the monthly payment and the five-year total, the decision is easy. If it wins on one and loses on the other, the break-even year decides it. Ask each loan officer for a written Loan Estimate rather than a verbal quote, since the estimate is the document that legally locks in the fees you’re comparing.