SAFE MLO Test Math: The Calculations on the Outline, With Worked Examples

NMLS doesn't say how many SAFE MLO questions involve math, but the topics are predictable: its outline lists exactly five financial calculations under Mortgage Loan Origination Activities, and a handful of related terms elsewhere. Every example below is Passy's own, with round numbers chosen so you can check each step on the same kind of calculator you'll have: NMLS's FAQ says the test center provides a basic four-function calculator and a whiteboard for scratch work (online testing, for approved accommodation candidates, has an on-screen calculator and scratchpad).

The math NMLS's SAFE MLO outline lists

• Financial Calculations (under Mortgage Loan Origination Activities): periodic interest, monthly payments, down payments, closing costs and prepaids, and ARM adjustments to interest rates and payments
• Qualifying ratios (also under origination activities): LTV and debt-to-income
• Financial terms (under General Mortgage Knowledge): discount points, the 2-1 buydown, LTV, accrued interest, finance charges, daily simple interest, and APR

The SAFE MLO formula sheet

Rounding: keep the unrounded figures until the end, then round to cents. If your answer is a few cents off every choice, a rounded intermediate step is the usual cause.

Interest and payment calculations, worked

Monthly interest. A $240,000 balance at 6.5%: $240,000 × 0.065 = $15,600 a year; ÷ 12 = $1,300 a month.

Interest-only payment. A $200,000 interest-only loan at 7%: $200,000 × 0.07 ÷ 12 = $1,166.67.

Amortizing payment. A fully amortizing payment comes from the formula P × r(1 + r)ⁿ ÷ ((1 + r)ⁿ − 1), where r is the monthly rate and n the number of payments. For $300,000 at 6% over 30 years (r = 0.005, n = 360), it's $1,798.65. Raising 1.005 to the 360th power isn't practical on a four-function calculator, so practice the factor method: the payment factor for 6% and 30 years is about $5.9955 per $1,000, so 300 × $5.9955 = $1,798.65. If a question gives you a factor, multiply; if it doesn't, check whether it's actually asking for the interest portion.

Splitting the first payment. Of that $1,798.65, the first month's interest is $300,000 × 0.06 ÷ 12 = $1,500, so $298.65 goes to principal, and the balance falls to $299,701.35. Each later month's interest is figured on the new, lower balance, which is why the principal share grows over time.

Down payment, LTV and CLTV

A buyer agrees to pay $400,000. The home appraises at $390,000, and the loan is $351,000.

• Down payment: $400,000 − $351,000 = $49,000. It's measured against the price the buyer pays
• LTV: $351,000 ÷ $390,000 = 90%. Fannie Mae's Selling Guide (B2-1.2-01) divides by the lower of the sales price or the appraised value for a purchase, and for a refinance by the appraised value. Dividing by the $400,000 price would give 87.75%, the trap answer
• CLTV: with a $320,000 first mortgage and a $40,000 second on a $400,000 value, ($320,000 + $40,000) ÷ $400,000 = 90% (Fannie Mae B2-1.2-02 adds the drawn HELOC balance and unpaid closed-end subordinate balances)

Fannie Mae truncates the result to two decimals and rounds up to the next whole percent, so 94.01% is delivered as 95%. Lender rounding rules vary; on the test, use what the question gives you.

Debt-to-income on the SAFE MLO Test

Regulation Z's ability-to-repay rule defines the monthly DTI ratio as total monthly debt obligations (including the new loan's payment, mortgage-related obligations such as taxes and insurance, simultaneous loans, current debts, alimony and child support) divided by total monthly income (12 CFR 1026.43(c)(7)).

A borrower earns $96,000 a year, so $8,000 a month gross. The proposed housing payment, with principal, interest, taxes, insurance and HOA dues, is $2,100. Other debts: a $450 car payment, a $250 student loan and a $100 minimum card payment.

• Total debts: $2,100 + $450 + $250 + $100 = $2,900
• DTI: $2,900 ÷ $8,000 = 36.25%
• Housing-only ratio, if a question asks for one: $2,100 ÷ $8,000 = 26.25%

There's no federal DTI cap in the current qualified-mortgage rule; investor limits apply instead. Under Fannie Mae's Selling Guide (B3-6-02), 36.25% would be over the 36% maximum for a manually underwritten loan, but within the 45% allowed with credit score and reserve requirements, and within the 50% limit for loans underwritten through its DU system. Formulas like these are what the planned flashcards for LTV, DTI and points formulas are for.

Points, prepaid interest and escrow

Discount points. One point is 1% of the loan amount; the Loan Estimate shows points both as a percentage of the amount of credit and in dollars (12 CFR 1026.37(f)(1)(i)). 1.5 points on a $320,000 loan: $320,000 × 1.5 ÷ 100 = $4,800.

Prepaid (per diem) interest. The Loan Estimate line reads "Prepaid Interest ( __ per day for __ days @ __ %)" (1026.37(g)(2)(iii)). A $365,000 loan at 6% closes on June 18, and interest is collected for June 18 through June 30, which is 13 days:

• Daily interest: $365,000 × 0.06 = $21,900; ÷ 365 = $60.00
• Prepaid interest: $60.00 × 13 = $780.00
• With a 360-day year, the daily figure would be $60.83 and the total $790.83, so read which convention the question uses

Monthly escrow and the cushion. Annual taxes of $4,800 and insurance of $1,500 make $6,300 a year, or $525 a month added to principal and interest. Regulation X caps the cushion a servicer may hold at one-sixth of the estimated annual disbursements (12 CFR 1024.17(c)): $6,300 ÷ 6 = $1,050.

ARM adjustments and caps, worked

An ARM's rate after the fixed period is the index plus the margin, which Fannie Mae calls the fully indexed rate (B2-1.4-02), limited by the caps the Loan Estimate shows in its Adjustable Interest Rate table: the maximum first change, the maximum later changes, and the minimum and maximum rates (1026.37(j)).

Passy example: a 5-year ARM starts at 5.50% with a 2.75% margin. Its caps are 2 points at the first change, 1 point at each later change, and 5 points over the start rate for life.

The payment is then recalculated on the remaining balance over the remaining term. For a $300,000, 30-year loan in this example, the payment of $1,703.37 at 5.50% would become about $1,916.46 at 6.75% on the remaining balance of about $277,382 after 60 payments, which takes a financial calculator; on the test, expect to compute the rate and to reason about the payment's direction. Fannie Mae's ARM rules add that a rate can never fall below the margin, and Fannie Mae rounds index plus margin to the nearest one-eighth of a percent when it computes the fully indexed rate; the index values here were chosen so no rounding is needed. If a question gives a rounding rule, apply it before the caps.

Buydowns, PMI and cash to close

2-1 buydown. Passy example: on a $300,000, 30-year loan at a 7% note rate, a 2-1 buydown in this example lowers the rate to 5% in year 1 and 6% in year 2.

• Payments: $1,995.91 at 7%, $1,610.46 at 5%, $1,798.65 at 6%
• Year 1 subsidy: ($1,995.91 − $1,610.46) × 12 = $4,625.40
• Year 2 subsidy: ($1,995.91 − $1,798.65) × 12 = $2,367.12
• Total buydown cost: $6,992.52

Fannie Mae requires the lender to qualify the borrower at the note rate, not the bought-down rate, and its buydown plans can't cut the rate by more than 3% or raise it by more than 1% a year (B2-1.4-04).

PMI cancellation points. With an original value of $300,000 (the lower of price and appraised value, per 12 U.S.C. 4901), borrower-requested cancellation is available at 80%, a $240,000 balance, and automatic termination comes at 78%, $234,000, on the original amortization schedule. PMI's 80% and 78% marks are in the planned SAFE MLO flashcard deck.

Cash to close. The Loan Estimate builds it from the total closing costs, the down payment, the deposit, seller credits and other adjustments (1026.37(h)). Using the $400,000 purchase above:

Finance charge, amount financed and APR without a formula

The APR isn't something you'll calculate by hand, but the concepts are tested. The finance charge includes interest, points, loan fees and mortgage insurance premiums (12 CFR 1026.4(b)), while bona fide title, appraisal, credit report and notary fees are excluded for real estate loans (1026.4(c)(7)). The amount financed is the loan amount minus prepaid finance charges (1026.18(b)).

Passy example: a $300,000 loan at 6% with $4,800 in points and a $1,200 origination fee, both prepaid finance charges, has an amount financed of $294,000. The borrower repays the full $300,000 at $1,798.65 a month, which works out to an APR of about 6.19%, higher than the 6% note rate. The more prepaid finance charges, the wider the gap. And a disclosed APR is accurate if it's within 1/8 of a percentage point (1026.22(a)(2)).

A Passy math practice question

This is an original Passy practice question, not an NMLS test item.

A buyer contracts to pay $250,000 for a home that appraises at $262,500 and makes a 10% down payment. What is the LTV?

• A. 10.0%
• B. 85.7%
• C. 90.0%
• D. 94.5%

Answer: C. The loan is $250,000 − $25,000 = $225,000. For a purchase, LTV is measured against the lower of price and appraised value, $250,000, so $225,000 ÷ $250,000 = 90%. A is the down payment percentage, not the LTV; B divides by the appraised value ($225,000 ÷ $262,500 = 85.7%); D treats 90% of the appraised value ($236,250) as the loan and divides it by the price.

Next step for SAFE MLO math

Copy the formula sheet by hand, then redo each worked example above without looking, using only the four functions. When the steps feel automatic, try the free SAFE MLO practice questions, and see the origination activities guide for where each number sits in a loan file. For tougher repetition, Hard Mode challenges are planned for full SAFE MLO prep.