A 580 credit score sits exactly on the FHA line. That number is what separates a 3.5% down payment from a 10% one, and it’s the reason so many people run an FHA loan calculator with 580 typed into the credit field. The problem is that most calculators treat the score as a footnote. You enter a sales price, it returns a payment, and that payment looks noticeably friendlier than what a lender will quote you a week later.
Here’s what the math actually looks like at 580, and where the online tools tend to lead you wrong.
What a 580 Credit Score Really Unlocks
FHA guidelines are written in tiers, and the down payment requirement is the most consequential one:
- 500 to 579: 10% down payment required
- 580 and above: 3.5% down payment allowed
- Below 500: no FHA financing at all
So a 580 gets you the cheapest entry point FHA offers. What it doesn’t do is guarantee a lender will approve you. Banks and mortgage companies add their own credit floors on top of FHA rules, and plenty of them set that floor at 620 or 640. A 580 makes you eligible on paper. Finding a lender who will actually fund the loan takes phone calls, not a calculator.
Debt-to-income matters just as much at this score. With a 580, the automated underwriting system tends to be stricter about how much of your monthly income goes toward housing plus all other debt payments. A payment that fits comfortably at a 700 score may get flagged at 580 if your DTI lands above roughly 43%.
The Three Inputs That Move the Number Most
Your interest rate
FHA doesn’t set rates by credit tier. Lenders do. At 580, expect a rate somewhere between half a point and a full point above whatever headline rate you see advertised, because pricing is risk-based. That gap is worth real money. On a $270,000 loan, a 0.75% rate difference is roughly $130 a month.
Mortgage insurance
This is where most calculators quietly understate the total. FHA loans carry two mortgage insurance premiums: an upfront charge of 1.75% of the base loan amount, usually rolled into the loan balance, and an annual premium of 0.55% of the loan amount, billed monthly. On a $270,000 base loan, that annual premium runs about $124 a month. Any calculator that leaves MIP out is showing you a payment that doesn’t exist.
Property taxes and homeowners insurance
Escrow items vary wildly by county. Two houses on the same street in different school districts can carry tax bills that differ by $200 a month. An FHA loan calculator only knows what you type in, so pull the actual tax figure from the county assessor’s site rather than accepting a default.
A Realistic Example: $275,000 Purchase at 580
Say you’re buying at $275,000 with 3.5% down. That’s $9,625 out of pocket, leaving a base loan of $265,375. The upfront MIP adds about $4,644, so the loan you actually repay is roughly $270,019. At a 6.75% rate over 30 years, principal and interest comes to about $1,751 a month. Add the $122 monthly mortgage insurance, $260 in property taxes, and $110 for homeowners insurance, and you’re at roughly $2,243.
Drop the rate to 6.25% and that payment falls to about $2,160. Push it to 7.25%, which is realistic for a 580 in a tight market, and you’re near $2,330. Same house, same down payment, $170 a month of variance based purely on where your score lands you in lender pricing.
A 3.5 percent down FHA calculator is the right tool for this exact scenario, since it’s the down payment tier your 580 unlocks. Run it with your own rate estimate rather than the default.
Reading the Result Without Fooling Yourself
The first number a calculator shows you is the floor, not the ceiling. Three things typically get added after the fact:
- Seller concessions can reduce your closing costs but won’t touch the monthly payment
- HOA dues, if the property has them, count against your DTI and aren’t in most default calculators
- Escrow cushion adjustments can nudge your monthly payment up $20 or $30 in the first year
There’s also a purchase-price ceiling to consider. FHA caps loan amounts by county, ranging from roughly $498,257 in low-cost areas up to $1,209,750 in high-cost ones for 2025. If the house you want exceeds the local limit, the calculator will happily compute a payment for a loan you can’t get. Check the FHA loan limits by county before you fall in love with a listing.
What the 580 Usually Costs You Over Time
FHA mortgage insurance doesn’t disappear at 20% equity the way conventional PMI does. If you put 3.5% down, that 0.55% annual premium stays for the life of the loan unless you refinance into a conventional product later. At $122 a month over 30 years, that’s north of $43,000.
This is the practical argument for treating 580 as a starting line rather than a finish line. Six to twelve months of on-time payments, a paid-down card balance, or a credit repair letter removing an erroneous collection can push you into the 620s, which opens up conventional loan pricing and a path to dropping mortgage insurance. Doing a rate-and-term refinance at that point is often worth more than any down payment assistance program you’d qualify for now.
It’s also worth knowing how bad-credit pricing shifts the whole picture, which the breakdown of what FHA calculators show borrowers with damaged credit covers in detail.
Three Calculations Worth Running Before You Tour a House
Most people run one calculator once and treat the output as gospel. Run three, and you’ll have a much clearer picture of your actual range.
Start with affordability. Work backward from your monthly income rather than forward from a sales price. A lender will approve you for more than you’ll enjoy paying. The FHA affordability calculator helps you find the payment that leaves room for car repairs and groceries, not just the one that clears underwriting.
Then check the payment accuracy. Compare a generic mortgage calculator against one built for FHA specifically, and see whether mortgage insurance, the upfront MIP, and the escrow line items all appear. A calculator built for FHA loans should show those separately, because each one behaves differently over time.
Finally, get a real quote. Calculators work from estimates. A loan officer pulls your actual tri-merge score, which may differ from the free score you’re looking at by 10 to 30 points in either direction, and that difference can move your rate. At a 580, ask specifically whether the lender has a credit overlay above FHA’s minimum and what their lowest published score is. A few phone calls here will save you more than hours of tweaking numbers on a screen.
The number that matters isn’t the one the calculator shows on the first screen. It’s the one on the Loan Estimate that arrives three days after you apply. Get those two as close together as you can before you start shopping.