How Lenders Size a Conventional Loan Under Fannie Mae vs Freddie Mac

The Quick Read: a lender tests your file against three ceilings, and the lowest one sets your maximum. Those ceilings are the county loan limit, the loan-to-value cap, and the debt-to-income test. Freddie Mac uses almost the same three tests, so for most buyers the two agencies produce nearly the same answer. The differences show up at the edges: automated tools, small-down-payment programs, and multi-unit homes.

Here is the honest answer on who each is for. Neither agency is “better” in general. Fannie Mae and Freddie Mac do not lend you money. They buy loans from lenders, and the lender picks which rulebook to sell into. Many buyers never choose between them. You choose between lenders and loan structures, and the agency follows. In the conventional loan programs Lendmire arranges through wholesale lenders, the core numbers line up closely enough that the file, not the logo, decides the outcome.

Side-by-Side

The table below covers the main sizing factors for a home you will live in. Program figures reflect the wholesale conventional programs Lendmire places files with, and all are subject to lender guidelines and full file review.

Two things stand out. First, the leverage rows match on the standard one-unit purchase. Second, the real gaps sit in the multi-unit row and the automated-underwriting rows. Those are worth understanding before you pick a loan structure.

The Three Ceilings That Size a Loan

A conventional loan is capped three ways, and your loan can be no larger than the smallest cap.

Ceiling one: the conforming loan limit. The FHFA sets a loan limit by county and unit count, and it is the same for Fannie Mae and Freddie Mac. Orrick’s summary of the FHFA announcement explains that the limit has a baseline and a higher ceiling for costly counties. Look up your own county’s figure in the FHFA’s current list, because it changes. A loan above the limit is a jumbo loan, which sits outside the Fannie and Freddie framework.

Ceiling two: the LTV cap. LTV is the loan divided by the home’s value. On a purchase, the lender uses the lower of the appraised value or the price you pay. The cap shifts with occupancy and unit count. On a one-unit principal residence, the parameters Lendmire works with allow 97% LTV (3% down) with a fixed rate when at least one borrower is a first-time buyer, meaning no ownership interest in a home in the prior three years. Otherwise the cap is 95% (5% down). Two- to four-unit principal residences go to 95%. Second homes go to 90%. Occupancy decides leverage, and that is the whole story on non-primary homes. Every figure here varies by lender and program — guidelines, property type, leverage, and credit profile all apply.

Ceiling three: the DTI test. DTI is your monthly debts divided by your stable monthly income. Freddie Mac’s Guide Section 5401.2 defines it as the housing expense plus liability payments over stable income or qualifying assets. Fannie Mae’s Selling Guide B3-6-02 sets the standard on its side. This ceiling is where most buyers hit their real limit.

Which ceiling binds depends on the buyer. A high earner with a big car loan and student debt usually hits DTI first. A buyer with little saved hits LTV first. A buyer in a high-priced county can hit the loan limit before either.

How the Sizing Sequence Runs

Lenders do not run one calculation. They run a sequence, and each step can change the answer.

1. Income and debts. The lender documents stable income and lists every monthly liability on your credit report.

2. Qualifying payment. The housing payment includes principal, interest, property taxes, insurance, mortgage insurance if it applies, and any association dues.

3. DTI check. Housing payment plus other debts, divided by income, must fit the ratio ceiling for your underwriting path.

4. LTV check. The loan amount against the lower of price or appraised value must fit the cap for your occupancy and unit count.

5. Limit check. The loan must sit at or under the county limit for the number of units.

6. Automated finding. The file goes through DU or LPA, which weighs the whole risk picture rather than a single number.

7. Lender overlays. The lender may add stricter rules of its own on top of the agency’s.

Step six matters more than most buyers expect. A file can fit every written ceiling and still draw a weaker finding because of how several factors combine. A larger down payment, a paid-off debt, or a co-borrower can improve that finding.

DTI at Each Agency: Where the Two Really Differ

On paper, the two agencies look alike. Fannie Mae’s automated ceiling for DU is a 50% total ratio. For manual underwriting, the base maximum is 36%, and the loan becomes ineligible above 45%. Between those figures, the credit score and reserve factors in the Fannie Mae Eligibility Matrix apply. Freddie Mac follows a similar manual pattern, with 36% as the guideline and loans above 45% ineligible.

The automated side is where Freddie Mac differs. Its guide says LPA calculates and assesses the qualifying ratios. It does not print a flat 50% ceiling the way Fannie Mae does.

Even Fannie’s 50% is not a promise. DU must return an Approve/Eligible finding, and it weighs credit, reserves, LTV, and more. A 50% ratio with a thin file can fail. A 46% ratio with strong credit and reserves can pass.

A few rules apply at both agencies:

• Installment debts with only a few payments left may be excluded from DTI. Lenders count the ones with a long way to go.
• If you pay off a debt to qualify, the lender must document where the money came from.
• If you take on a new debt before closing, the lender re-underwrites. Fannie Mae’s guide makes the loan ineligible if the recalculated ratio passes its ceiling for the path used.

Worked Examples: Which Ceiling Binds

These use percentages and plain words only. No dollar figures.

The heavy-debt earner. Picture a buyer with strong income and good credit, but a long car loan and large student payments. Her down payment clears a 95% cap easily. The loan limit is far away. The DTI test is the one that binds, so the maximum comes from the payment she can carry. Paying off the car loan, with funds documented, may raise her ceiling. Adding a co-borrower with income can too.

The small-saver first-time buyer. Say you are buying a one-unit home as a first-time buyer and have saved for 3% down. The 97% cap is your ceiling. Because LTV is that high, mortgage insurance applies, and it adds to the qualifying payment. At 97% on Fannie Mae, the loan must be fixed rate on a one-unit principal residence and run through DU. Both agencies also offer affordable-lending paths with an income limit of 80% of area median income. Final terms depend on lender guidelines, property type, leverage, and the borrower’s complete credit picture.

The high-cost-county buyer. Consider a buyer in a county where prices sit above the baseline limit. Her income and down payment are fine, but the county’s limit caps the loan. If the loan amount is above it, she is in jumbo territory. A larger down payment can pull the loan back under the limit. That is a real lever in the high-priced counties, and a lookup beats guessing.

The two-unit buyer. Imagine a buyer purchasing a duplex to live in one side. On the programs Lendmire works with, a two- to four-unit principal residence can go to 95% LTV. Freddie Mac’s manual and super-conforming paths apply lower caps on those homes, so the agency choice can matter here. The lender’s automated findings and overlays usually decide which path is practical.

When Fannie Mae Is the Better Fit

Fannie Mae tends to fit when your file benefits from a clear automated ceiling and a well-defined 97% option.

• You want a stated ratio ceiling. DU’s 50% total ratio gives a defined outer limit. Your file still needs a strong finding.
• You are a first-time buyer at the top of the leverage range. Fannie Mae’s 97% options page lays out the rules. The loan must be fixed rate and a one-unit principal residence, it must go through DU, and loans above 95% LTV require DU. ARMs and high-balance loans are not eligible for 97% financing. If every borrower who will occupy the home is a first-time buyer on a purchase above 95% LTV, at least one must complete homeownership education.
• You qualify for an affordable program but are not a first-time buyer. Fannie Mae’s HomeReady uses an income limit of 80% of area median income and does not require a first-time buyer.
• You are using a co-borrower who will not live in the home. Fannie Mae’s HomeReady matrix treats non-occupant borrowers in a defined way. Check current terms with your loan officer. These specifics are subject to lender guidelines and a full review of property, leverage, and credit.

When Freddie Mac Is the Better Fit

Freddie Mac tends to fit when the lender’s tools and the file line up with its structure.

• Your lender sells most of its loans to Freddie Mac. The lender’s channel often picks the agency, and a file that is fine at one agency is usually fine at the other.
• Your file reads better to LPA. Because Freddie Mac assesses the ratios inside its automated system, some files with an unusual profile return a better finding there. That varies file by file, and a loan officer can run the file both ways.
• You are juggling a second loan. Freddie Mac defines combined LTV for a first lien plus any disbursed second financing. It counts the full credit limit of a home equity line, used or not. Check how your lender handles a second lien before you commit.
• You like Home Possible’s structure. Mortgage insurance on a one-unit home can be cancelled when the balance falls below 80% of the home’s value.

One small Freddie Mac detail: it rounds an LTV up to the next whole percent. A loan at 94.1% is treated as 95%.

Mortgage Insurance: The Same Mechanics at Both

Mortgage insurance is required above 80% LTV at both agencies. You can request cancellation when your balance reaches 80% of the original value, if payments have been on time, there are no subordinate liens, and the value has not dropped. The servicer must end it automatically at 78%, under the Homeowners Protection Act. Premiums vary by credit score and LTV, and the quote on your Loan Estimate is the number to rely on. Terms depend on the lender’s guidelines, the property type, the leverage, and a full review of the credit profile.

Mortgage insurance feeds back into sizing. It raises the qualifying payment, which uses up room under the DTI ceiling. That is one reason a 3% down payment can shrink the maximum loan more than the LTV cap alone suggests. The exact numbers vary by lender and program and follow a full review of property, leverage, and credit.

Why Two Lenders Give Different Answers

The agencies set a floor. Lenders can add stricter rules, called overlays. The wholesale conventional programs Lendmire places files with start at a 620 decision score, and some lenders set a higher one. One lender may cap its own ratio below the agency’s. Another may want more reserves on a thin file. That is how the same borrower sees different maximums from two lenders under the same agency’s rules.

Lendmire is a mortgage broker, not a lender. Its role is to compare wholesale options so you see more than one set of overlays against your file. Waiting periods after credit events are agency rules and apply across lenders: four years from a chapter 7 discharge, seven from a foreclosure, and four from a short sale or deed-in-lieu. Documented extenuating circumstances can shorten them.

How to Raise Your Maximum Loan

You can move each ceiling, though not all of them.

• Pay down or pay off debts. This directly lowers DTI. Document where the funds came from.
• Add a qualified co-borrower. More income can lift the DTI ceiling, though their debts count too.
• Put more down. A lower LTV can improve the automated finding and cut or end mortgage insurance.
• Raise the credit score. A stronger score improves the automated finding and may open better terms.
• Hold new debts until after closing. A new car loan before closing triggers a re-underwrite.
• Check the county limit. If you are near it, a bigger down payment can keep you in conforming territory.

Appraisals and the Waiver Question

A full appraisal is the default. Both agencies can offer an appraisal waiver based on their own data, Fannie Mae through Value Acceptance and Freddie Mac through ACE. You cannot request one. The agency’s automated system offers it on a specific loan. A waiver may remove the appraisal fee, but you cannot count on it when budgeting. Waiver rules and thresholds change, so ask your loan officer about the current ones instead of assuming.

Key Terms Defined

Conforming loan: a loan at or under the county limit that meets Fannie Mae or Freddie Mac rules, which lets the lender sell it to one of them.

Loan-to-value (LTV): the loan amount divided by the home’s value, which sets your minimum down payment.

Debt-to-income (DTI): your monthly debts, including the new housing payment, divided by your gross monthly income.

Automated underwriting: software, DU at Fannie Mae and LPA at Freddie Mac, that weighs your whole risk profile and returns a finding.

Overlay: a rule a lender adds on top of the agency’s, which can make it stricter than the agency requires.

Mortgage insurance: coverage that protects the lender when you borrow above 80% LTV, and that ends on a set schedule as you pay down the loan. Final terms depend on the lender’s guidelines, the property type, and the borrower’s complete credit picture.

The Verdict

If your file is clean and standard, expect Fannie Mae and Freddie Mac to size it almost the same. The tie-breakers are practical. Fannie Mae offers a stated DU ceiling and a well-documented 97% path. Freddie Mac offers Home Possible and a different automated read, and it applies lower caps on some multi-unit paths. The lender’s channel often decides, and a good broker will compare outcomes across lenders instead of fixating on the agency.

If you are buying a home and want to see whether a conventional loan fits your file, Lendmire can help you compare the options and what each one asks of the file.

For your own numbers, request a scenario review with Lendmire.

About Lendmire

Lendmire (NMLS# 2371349) is a mortgage broker licensed for consumer lending in 16 states. Lendmire arranges FHA, VA, conventional and jumbo purchase and refinance loans through wholesale lenders; every file is underwritten by the lender under the applicable program guidelines. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.

References

1. Orrick: FHFA Announces Increases to Conforming Loan Limits

2. Freddie Mac Seller/Servicer Guide Section 5401.2

3. Fannie Mae Selling Guide B3-6-02, Debt-to-Income Ratios

4. Fannie Mae Eligibility Matrix

5. Fannie Mae FAQs: 97% LTV Options

6. Fannie Mae: 97% Loan-to-Value Options and HomeReady