Mortgage Escrow Calculator

Introduction to escrow analysis under Regulation X

A mortgage escrow account — called an impound account or reserve account in some states — is an account a servicer establishes or controls on behalf of a borrower to pay property taxes, insurance premiums and similar charges on a federally related mortgage loan. The account is not a savings plan and it is not a discretionary buffer: since 1976 the Real Estate Settlement Procedures Act (RESPA, 12 U.S.C. 2609) and its implementing Regulation X have capped what a servicer may collect, and since 1996 every servicer has been required to use one specific accounting method. That method is aggregate analysis, and the arithmetic is spelled out step by step in 12 CFR 1024.17(d)(2) and Appendix E to Part 1024.

Almost every escrow calculator on the web stops at "annual taxes plus annual insurance, divided by twelve". That number is correct as far as it goes — it is the base payment defined in 12 CFR 1024.17(c)(1)(ii) — but on its own it answers none of the questions homeowners actually have. It cannot tell you how much cash you must bring to settlement, because that depends on when the tax collector bills you. It cannot tell you whether your account will dip below zero in November, because a payment stream of equal twelfths against two lumpy tax instalments is not a flat line. And it cannot separate a cushion (a permitted buffer that sits at the bottom of the account all year) from a shortage (a deficit you are being asked to repay), which is the single most common source of confusion when an annual escrow statement raises a monthly payment by two hundred dollars.

This calculator models the disbursement calendar month by month. It builds the trial running balance described in the regulation, finds the projected low point, applies the aggregate adjustment that lifts that low point to zero, adds the permitted cushion on top, and then compares the resulting target balance with the balance you actually hold. What comes out is the set of numbers that appear on a real initial or annual escrow account statement: the base monthly escrow payment, the required cushion, the low-point month and balance, the shortage or surplus, and the adjusted payment you will be billed.

How to use the escrow analysis inputs on this page

Work through the form in the order the fields appear; each one maps to a line on your escrow statement or a bill you already have in a drawer.

• Annual property tax — the full twelve-month tax liability for the property, not one instalment. If your county bills in two halves of $2,850 each, enter $5,700.
• Tax bill schedule and first disbursement month — how many times a year the servicer actually pays the tax office, and the calendar month of the first payment. This is the field that drives the low point. Quarterly billing smooths the curve; a single annual lump sum makes it deep.
• Annual homeowners insurance premium and renewal month — insurance is normally paid once a year on the policy anniversary, so only one month is needed.
• Escrowed mortgage insurance — the annual total of any FHA MIP, USDA annual fee or conventional PMI that your servicer remits from the escrow account. It is modelled as twelve equal monthly disbursements because that is how these premiums are remitted, so it raises the payment without deepening the low point. Leave it at zero if your mortgage insurance is billed outside escrow or you have none.
• Cushion, in months — 0, 1 or 2. Two months is the federal maximum. Enter a smaller figure if your state or your note requires one.
• First month of the computation year — the month of your first payment into the account. Regulation X defines the escrow account computation year as the twelve months beginning with the initial payment date.
• What you are analysing — this matters, because the same arithmetic produces two different answers. For a new account funded at settlement, the gap between the target balance and what you already hold is collected once, as the initial escrow deposit permitted by 12 CFR 1024.17(c)(1)(i); it appears on your Loan Estimate and Closing Disclosure and does not change your monthly payment. For an existing account at annual analysis, the identical gap is a shortage and is repaid in equal instalments over at least twelve months under 12 CFR 1024.17(f)(3), which does raise your monthly payment.
• Escrow funds already on deposit — the balance at the moment of the analysis. Leave it at zero for a brand-new account; enter the figure from your annual statement to test for a shortage or surplus, and enter a negative number if the account is overdrawn.
• Monthly principal and interest — optional, used only to show the full monthly housing payment.

Press Run escrow analysis and the page returns a summary, a thirteen-row trial running balance, and a chart of the projected balance against the cushion floor. The schedule can be downloaded as CSV so you can set it beside your servicer's statement line for line.

The aggregate accounting formula that governs an escrow payment

Start with the estimated total annual disbursements. Regulation X requires the servicer to use the known charge where it knows it, and otherwise the prior year's charge, optionally indexed by the most recent change in the national Consumer Price Index for all urban consumers (12 CFR 1024.17(c)(7)). Writing for the annual property tax, for the annual insurance premium and for other escrowed items, the annual total is

Formula: A = T + I + O

Section 1024.17(c)(1)(ii) then fixes the base monthly escrow payment at one-twelfth of that total. This is the only recurring escrow charge the regulation permits in the ordinary case:

Formula: E = A / 12

The cushion is a balance, not a payment. Section 1024.17(c)(5) caps it at one-sixth of estimated annual disbursements, and section 1024.17(d)(2)(i)(C) describes the identical quantity as two months of the borrower's escrow payments. With as the number of cushion months a servicer elects to hold,

Formula: C = min ⁡(k ⋅ E, A / 6)

Because , the two statements of the cap are algebraically the same number, and the binding constraint is simply . Nothing in Regulation X requires a cushion at all; is lawful.

Now the part that generic calculators omit. Let be the disbursement made in month of the computation year, with and . Step 1 of Appendix E builds a trial running balance from a zero opening balance, crediting the payment and debiting the disbursement in each month:

Formula: B_0 = 0, B_m = B_m−1 + E − D_m

Since the twelve payments sum to exactly the twelve disbursements, , and the trial balance necessarily dips negative somewhere unless every disbursement is monthly. Step 2 lifts the whole curve by the depth of that dip — the aggregate adjustment:

Formula: Δ = − min 0 ≤ m ≤ 12 B_m

Step 3 adds the cushion, giving the target balance for every month of the year:

Formula: t_m = B_m + Δ + C

Two consequences follow immediately and both are stated in the regulation. First, the low point of the target schedule equals the cushion exactly, , which is why section 1024.17(d)(2)(ii) says the lowest monthly target balance may not exceed one-sixth of annual disbursements. Second, the deposit required to open the account is the month-zero target, — the figure that appears on your Loan Estimate and Closing Disclosure as prepaid escrow, and the reason two identical loans on identical houses can require wildly different cash at closing purely because of the tax calendar.

At an annual analysis the account already holds a balance . Comparing it with the target produces the three terms defined in section 1024.17(b):

Formula: S = max ⁡(0, t_0 − B), U = max ⁡(0, B − t_0), F = max ⁡(0, − B)

where is the shortage, the surplus and the deficiency. A shortage of one month's escrow payment or more may be collected in equal instalments over at least twelve months under section 1024.17(f)(3)(ii), so the payment you are actually billed is

Formula: E_billed = E + S / 12

and the full monthly housing payment, with principal and interest , is . Note that the shortage repayment is temporary and drops off after twelve months; the cushion, once funded, stays in the account.

Worked example: two tax instalments and a March renewal

Take a house with a $6,000 annual property tax bill collected in two equal instalments in November and May, a $2,100 homeowners insurance premium renewing in March, no escrowed mortgage insurance, a two-month cushion, and a computation year that starts in January. Annual disbursements are , so the base monthly escrow payment is and the permitted cushion is .

The trial running balance climbs $675 a month from January, drops $2,100 in March, drops $3,000 in May, climbs again through the summer and drops $3,000 in November, ending the year back at zero. Its minimum is −$1,725 at the end of May, so the aggregate adjustment is and the required opening balance is . The low point of the target schedule then sits in May at exactly $1,350 — the cushion, untouched, as the regulation intends. A buyer closing on this house with nothing yet on deposit would see $3,075 of prepaid escrow on the Closing Disclosure and a monthly escrow charge of $675.

Now switch the calculator to existing account at annual analysis and suppose the analysis finds only $1,900 in the account. The shortage is . That exceeds one month's payment, so the servicer may spread it over at least twelve months: $1,175 ÷ 12 = $97.92 a month. The billed escrow payment becomes $772.92, and with $2,150 of principal and interest the full housing payment is $2,922.92 — until the shortage clears, after which it falls back to $2,825.00. Had the account instead held $3,300, the surplus of $225 would exceed the $50 threshold in section 1024.17(f)(2)(i) and would have to be refunded within 30 days rather than credited forward.

The table below shows how the same $8,100 of annual disbursements produces radically different opening deposits purely because of the billing calendar. The base payment of $675 never moves; the cash needed to fund the account at settlement ranges from $1,425 to $7,425. A borrower whose county bills in January and who closes in January is funding almost an entire tax year up front, while a borrower whose county bills in December has nearly twelve months of contributions in hand before the bill arrives.

Regulation X supplies its own illustration in Appendix E, and it is worth reproducing because it is the only officially sanctioned set of escrow numbers in existence. The example assumes $360 of school taxes disbursed on 20 September and county property taxes of $500 on 25 July and $700 on 10 December, a settlement on 15 May and a first payment on 1 July. Annual disbursements are $1,560, the monthly payment is $130, and the cushion is $1,560 ÷ 6 = $260. The initial trial balance bottoms out at −$780 in December, so the aggregate adjustment is $780 and the opening balance in Step 3 is $1,040 — precisely the figure printed in the appendix. This page's engine reproduces those three steps.

Reading the result: target balance, shortage, surplus and deficiency

The base monthly escrow payment is the recurring charge the servicer is entitled to collect indefinitely. If your statement shows a larger recurring number and no shortage line, ask why.

The projected low point is the diagnostic worth staring at. If it is at or above the cushion, the account is funded as the regulation contemplates. If it falls between zero and the cushion, the account is thin: it will pay its bills, but the buffer that exists to absorb a mid-year premium increase has been eaten. If it goes negative, the servicer will be advancing its own funds during that month and a deficiency will follow.

A shortage and a deficiency are not synonyms, and conflating them is the classic error. A shortage is a positive balance that is simply below target; a deficiency is a negative balance. The regulation treats them differently: a shortage of a month or more is repaid over at least twelve months, whereas a deficiency may be demanded in as few as two instalments under section 1024.17(f)(4). A surplus of $50 or more must be refunded within 30 days of the analysis if you are current on the loan; below $50 the servicer may refund it or credit it forward.

A large opening deposit is not a fee and it is not lost money. It is your money, held in the account, and it comes back to you as a surplus refund when the loan is paid off or the escrow account is closed. What it does affect is cash to close, which is why buyers closing a month before a big tax instalment often face a startlingly large prepaid-escrow line on the Closing Disclosure.

Limitations and assumptions behind this escrow projection

Every projection here rests on assumptions that are reasonable but not universal, and the limitations below are the ones most likely to move your number:

• Servicer practice and state law vary; this is an estimate. Section 1024.17(c)(8) makes clear that where a state statute or the mortgage documents specify a smaller cushion, that smaller limit controls. Several states restrict cushions below two months and some require interest to be paid on escrow balances. This page models the federal ceiling only.
• Instalments are assumed equal. Real tax bills often are not — the Appendix E example itself uses $500 and $700 halves. Unequal instalments shift the low point and change the aggregate adjustment. If your bills are lopsided, the opening deposit here will be approximately, not exactly, right.
• Disbursements are placed at month granularity. The regulation requires the servicer to disburse on or before the earlier of the discount deadline or the penalty deadline (section 1024.17(k)), and prohibits pre-accrual (section 1024.17(c)(6)). Whether a 3 November payment lands in the October or November row of a servicer's ledger can move a balance by one month's payment.
• Next year's bills are assumed known. Reassessments, millage changes, expiring homestead or senior exemptions, new special assessments for schools or sewers, and insurance renewals in catastrophe-exposed markets are all outside the model. Section 1024.17(c)(7) lets a servicer index an unknown charge by CPI, which this page does not attempt.
• The shortage is spread over exactly twelve months. That is the statutory minimum period, not a mandate; a servicer may use a longer period, may collect a sub-one-month shortage in 30 days, or may lawfully leave a shortage in place and do nothing.
• Escrowed mortgage insurance is modelled as twelve equal monthly disbursements. That matches how FHA MIP, USDA annual fees and monthly PMI are remitted, but a policy billed annually would change the low point. Enter such a policy under the insurance field instead.
• No interest, no fees, no negative amortisation. Balances are not credited with interest, and no servicing fees are deducted.
• Scope. Regulation X governs federally related mortgage loans on one-to-four family residential property. Commercial escrows, construction escrows, and accounts under a borrower's total control are outside section 1024.17 entirely.

Nothing on this page is legal, tax or financial advice. If your escrow analysis looks wrong, the productive next step is a written notice of error to your servicer under 12 CFR 1024.35, which obliges the servicer to respond within defined timeframes.

Sources and further reading

Primary source for every rule and constant used above: 12 CFR 1024.17, "Escrow accounts" (Regulation X, Consumer Financial Protection Bureau) — the aggregate accounting requirement at (c)(4), the one-twelfth base payment at (c)(1)(ii), the one-sixth cushion cap at (c)(5), the three arithmetic steps at (d)(2)(i), the lowest-monthly-balance limit at (d)(2)(ii), and the surplus, shortage and deficiency rules at (f)(2) to (f)(4). Read it at eCFR: 12 CFR 1024.17, with the worked arithmetic in Appendix E to Part 1024, "Arithmetic Steps". The underlying statute is the Real Estate Settlement Procedures Act, 12 U.S.C. 2609, "Limitation on requirement of advance deposits in escrow accounts" (U.S. Government Publishing Office); RESPA was administered by the U.S. Department of Housing and Urban Development until rulemaking authority transferred to the CFPB in 2011. Consumer-facing guidance: CFPB, "What is an escrow or impound account?" and the CFPB's interactive text of Regulation X section 1024.17. The Appendix E figures quoted above ($1,560 annual disbursements, $130 monthly, $260 cushion, $780 adjustment, $1,040 opening balance) were read from the eCFR text of the appendix, not from secondary summaries.

Common questions about escrow accounts and RESPA limits