Loan & Mortgage Tracker — Methodology Handbook

The Loan & Mortgage Tracker follows a mortgage, a car loan or any other loan against its own contract. You describe the loan once the way the agreement does — how much was lent and when, the rate, the term, how often you pay, how the payment is built and what rides along with it — and the tracker builds the schedule, follows the payments you actually make (on time, early, late, extra or missed), and tells you what is left, what the next payment will do, when the loan really ends and what it costs in total. This handbook explains what the tracker stores, how every figure is computed and what it deliberately does not do.

👉 Open the tracker: calculatorai.app/loan-tracker

A record and an estimate, not financial advice. The tracker applies the contract you describe to the payments you log. Your lender's statement is the official figure; when you enter a balance from it, the tracker follows the bank and shows any difference.

Who it is for

Anyone repaying a loan who wants to see it the way a good bank statement should show it: homeowners with a mortgage (fixed or adjustable), car buyers, students, small-business owners, and anyone paying ahead of schedule who wants to know what that saves. It works in any currency, for one loan or several, monthly, every two weeks, weekly, quarterly or yearly.

How it differs from the Debt Payoff Tracker

The Debt Payoff Tracker is for many debts at once — credit cards, loans, medical bills — and the order to pay them off in (snowball or avalanche). It knows each debt by a balance, a rate and a minimum payment. The Loan & Mortgage Tracker knows one loan in depth: its contract, its schedule and every payment against it. Use both: the debt tracker for the plan across everything you owe, this one for the mortgage or the car loan you want to follow closely.

The one idea everything follows from

A loan stores its contract and the payments that happened — everything else is worked out. The schedule, today's balance, the interest saved, the payoff date and the true cost are computed each time from the contract and the payments, never stored. Correct a payment or a rate and every figure follows at once.

The contract — what you enter

Name, look, type (mortgage, car, student, personal, business, home equity line, other) and lender.
Amount borrowed and currency.
Yearly rate and whether it is fixed or variable.
Term in years (plus extra months), start date (when interest starts) and first payment date — later due dates step from the first one (a loan paid on the 31st is paid on the last day of shorter months, never drifting to the 28th for good).
Payment frequency — monthly, twice a month, every two weeks, weekly, quarterly or yearly.
How the payment is built:
- Same payment (annuity) — the payment stays the same; interest shrinks and principal grows. Most mortgages and car loans.
- Equal principal — the same part of the loan is repaid every time plus interest, so the payment falls. Common in many European countries ("differentiated payment", Brazil's SAC).
- Interest only — only interest until the end, then the whole balance.

More terms (one tap away, with the usual defaults):

How interest is counted — a monthly rate (rate ÷ 12, most US mortgages and amortization tables), daily on a 365-day year (simple-interest car and personal loans), daily on a 360-day year (some business loans), daily on the actual days in the year (365 or 366 — the method many European banks state in their contracts), or Canadian (the quoted rate compounds twice a year, as Canada's Interest Act requires for fixed-rate mortgages).
Contract payment — if the agreement prints a payment slightly different from the formula, enter it: the bank's number wins. With no term entered, the term is worked out from it.
Interest-only periods at the start, then the loan amortizes over the rest; deferred periods with nothing paid and the interest added to the balance (student loans, payment holidays); a balloon left for the last payment.
What rides along with each payment and does not reduce the balance — escrow (property tax and home insurance), mortgage insurance (PMI/MIP), any other fee — and upfront fees paid once.
Home (or car) value at purchase and today — for equity, loan-to-value and the mortgage-insurance stop date.
Offset savings — for an offset mortgage, interest is charged on the balance minus the linked savings.
Overpayment allowance (% a year, of the balance at the start of the year or of the amount borrowed, by loan year or calendar year) and an early-repayment-charge ladder (a % until a date, then the next step).
I started tracking in the middle of the loan — enter the balance on a date from a statement; earlier payments are not needed.
Autopay (on by default) and how many days before a due date to be reminded.
The same loan in the Debt Payoff Tracker (pick it, and Net Worth counts it once) and Already counted in Net Worth (for a loan that is already there as a rental property's loan or a liability account).

The form shows what the contract works out to before you save — the payment, the payoff month, the total interest and the true yearly cost — so a typo in the rate is caught at once.

Payments — what you log

With autopay on, every due date with no entry counts as paid exactly as scheduled. You log only what differs:

Installment — a scheduled payment. It is matched to its own due date even when it was a few days early or late (within about 80% of a payment period).
Extra payment — money on top of the schedule. It pays any interest due first, then principal. You choose what your bank did with it: shorter term (the payment stays, the loan ends sooner — the bigger saving) or lower payment (the end date stays, every later payment is smaller).
Fee and escrow only — money paid that does not reduce the balance.
New borrowing — a draw on a credit line or a construction tranche.
Statement balance — no money moved: your bank shows this balance and the tracker continues from it.

Any payment can carry the bank's own split (principal and interest) and the balance it reports afterwards. When a reported balance differs from the tracker's own figure, the tracker follows the bank and says by how much it differed — usually rounding, fees or a different way of counting days.

With autopay off, a due date without a payment is shown as missed once it is more than about 80% of a period overdue; its interest stays owed and is paid first by the next payment.

A payment cannot be dated in the future — it has not happened yet.

Import from a statement (Pro)

Import in the header offers two ways in. From a photo, screenshot or PDF (Pro): it reads a photo, a screenshot or a PDF of a loan statement, a contract or its summary page, a payment history or your bank's app. What it finds is shown before anything is saved: the loan's terms can start a new loan (the loan form opens filled — you check and save), and every payment row it read is listed with a tick — rows already in the tracker (same day, same amount) are left unticked, and rows of a schedule that are still ahead are never imported. You can also record the statement's balance. The file stays in My files.

From a CSV file (free): a spreadsheet you kept, or the transactions export from your lender's online banking. Pick the loan the payments go to, check the columns it matched by itself (date and amount are needed; principal, interest, taxes & insurance, fees, the balance after, a type and a description are used when present), see the first rows, import. Comma, semicolon and tab files all read, in any date order the file is written in (03.04 is read as April 3rd when the column shows day-first dates). The sign of an amount is ignored, a row worded "additional principal" / «досрочное погашение» (or all principal and no interest) becomes an extra payment that shortens the term, and a row with only a balance becomes a statement balance. Left out and counted: rows on or before the date tracking starts (already inside the starting balance), rows dated in the future, and rows already logged — importing the same file twice adds nothing.

How each figure is computed

Interest accrues by the contract's method: once per period at the due date for the monthly and Canadian methods, by actual days between events for the daily methods (split at every rate change and, for the actual/actual method, at every new year). It is charged in whole cents (whole yen for zero-decimal currencies), as a statement shows it.
Every payment pays, in this order: what rides along (escrow, insurance, fees), the interest owed, then principal.
The contract schedule is the same walk with nobody deviating — so "interest saved" and "months saved" compare two runs of one calculation.
Interest saved = the contract's total interest − (interest already paid + interest still to pay on the real path).
Payoff date — the last projected payment if the contract is followed from today.
True yearly cost — the rate at which what you received (the amount borrowed minus upfront fees) equals every scheduled payment including insurance and fees, but not escrow (property tax and home insurance are not a cost of the credit). Shown as a yearly rate (US APR style) and as an effective rate (the EU and many other countries' "full cost of credit").
Equity — the value you entered minus what you owe on the loans secured on it (a mortgage and a home equity line both come off the home's value). Loan-to-value = balance ÷ value.
Mortgage insurance (US conventional loans) — the date the original schedule reaches 78% of the original value (when PMI must stop by law) and the date your real balance reaches 80% (when you can ask for it to be removed). After the 78% date the schedule stops adding PMI to the payment.
Overpayment allowance — the limit for the current allowance year, what you have overpaid in it and what is left; with an early-repayment-charge ladder, what paying the loan off today would cost (the charge on the part above the remaining allowance).
By year — interest, principal and other payments per calendar year. For past years this is what a lender's yearly interest statement (in the US, Form 1098) should show; future years are an estimate. Whether that interest is tax-deductible depends on your country and on the loan.

Variable rates

Each rate change is a date and a new rate, and you say what the bank did: recalculated the payment so the loan still ends on time (most adjustable-rate mortgages and most European variable loans) or kept the payment and moved the end date. If a rate rises so far that the payment no longer covers the interest, the tracker warns that the balance is growing.

Your overpayment plan

The Planner keeps your plan: an amount you intend to pay on top with every payment (from a date, until a date or until the loan is paid off), and one-off sums on future dates — a yearly bonus, a tax refund. Each says whether the bank should shorten the term or lower the payment. The plan is not a payment: nothing counts as paid until you record it. But the forecast follows it everywhere — the payoff date, the interest left, the schedule (planned rows are tagged), the calendar, the assistant — and the Planner shows the payoff date with the plan and without it, the interest it saves, how much is still planned and how much you have actually paid ahead so far. A one-off whose date has passed and was not recorded is shown as such, with a button to record it.

Tax deduction (an estimate)

For a mortgage in rubles or dollars the Loan tab estimates what comes back at tax time, with your own tax rate:

Rubles (Russia, Tax Code art. 220): your income-tax rate × the interest paid each year, until 3,000,000 ₽ of interest in total (390,000 ₽ at 13%), and the purchase deduction — your rate × the home's price up to 2,000,000 ₽ (260,000 ₽ at 13%), once in a lifetime, unless you tick that it is used. In a year no more comes back than the income tax paid that year; the rest carries over — the tracker does not know your income, so it says so.
Dollars (United States): the interest × your marginal rate, on the share of the loan up to $750,000, and only if you itemize (the standard deduction is shown to compare).

Past years use the interest you actually paid, later years the schedule. It is an estimate, not tax advice.

Which loan to pay ahead first

With two or more loans, the Overview takes a sum and applies it today to each loan as an extra payment that shortens the term, then ranks the loans by the interest it saves (in your header currency) with how many payments fewer and the new end date. A long loan can save more interest than a dearer short one — the money works longer; early-repayment charges and keeping a cash reserve are yours to weigh.

Milestones and copies

The balance bar marks a quarter, half and three quarters repaid and says when the next mark is reached; a notification celebrates each mark once. Copy loan (next to the pencil) opens a new loan with the same contract — a second similar loan, or a scenario to compare.

The end of a fixed rate

A fixed-rate loan can carry the date its fixed deal ends (a UK fix, a 5/1 ARM's first reset, a subsidised period) and the rate after it. From that date the forecast switches to the new rate and recalculates the payment — unless you entered what actually happened on that date as a rate change. The Loan tab shows "fixed until"; 90 days before, the tab, the calendar and a notification say the deal is ending, so there is time to compare a new one.

The planner — what if

From your real balance today (not from the original contract):

Extra each period, a lump sum on a date, or both — with shorter term or lower payment — shows the new payoff date, the interest saved, the interest left and the new payment, with both balance curves on one chart. A lump sum you actually made can be recorded on the loan from there.
Paid off by a date — pick the date you want to be done: the smallest extra each period that gets there (shorter term), the payoff date it gives and the interest it saves; one tap puts the amount into the what-if above. If the loan already ends by then, it says so; a date before the next payment, or one no payment could reach, is said to be out of reach.
Refinance check — a new rate, term and closing costs (paid now or added to the new loan): the new payment, the interest on the new loan, what you save or lose overall and how many payments it takes for the lower payment to repay the costs. A longer new term can lower the payment and still cost more overall; the planner says so.
If the rate goes up — for a variable rate (from the next payment) or a fixed deal with an end date (from that day): +1, +2 or +3 points, with the bank recalculating the payment — the new rate, payment, extra interest and end date. A stress test, not a forecast.
In today's money — the payments still ahead, discounted at a yearly inflation you set (a typical figure for the currency to start): a fixed payment gets lighter as prices rise.
Compare loan offers — up to three offers for the same amount (rate, term, fees up front, same-payment or equal-principal): the first payment, the interest, interest + fees and the true yearly cost with the fees; the cheapest is marked. Insurance and other bank charges are not included.

Nothing in the planner is saved — except your overpayment plan.

Where your loan goes next

Expenses — any payment can be sent to the Expenses Tracker: the Expenses form opens filled with the amount, the loan's currency, the date and a category by loan type (housing for a mortgage, transport for a car loan, education for a student loan); you check it and save.
Calculators — the Mortgage, Refinance, Loan payment and Car loan calculators sit beside the tracker.
Import — a CSV payment history (free) or a photo / PDF of a statement (Pro), see above.
PDF schedule — the Schedule tab's PDF button: the contract on top, every payment numbered (paid, autopay, missed, then the forecast after a "today" line), totals; free, like CSV.
Export — every loan with its full contract, every payment and rate change as CSV, and each loan's schedule as its own CSV. Free on every plan.

Shared loans

A joint mortgage or a family's loans can live in a shared space with the co-borrower or anyone you invite:

Admins add, edit and delete loans (a loan is what the space is made of) — including its fixed-rate end and the rate after it.
Editors log payments, import a CSV or a statement into a loan, enter rate changes and keep the overpayment plan (add, change, remove planned overpayments).
Viewers see everything and change nothing.
Everyone who writes needs their own Pro plan; viewing never does. A lapsed Pro keeps reading.
Each payment shows who added it.
Exporting the whole space is free for every member, always.
Your personal loans and the shared ones are never added together — the Overview's "which loan first" compares the loans of the book you are in.
The PDF schedule and CSV export work for every member.

Free and Pro

The whole tracker — unlimited loans and payments, the schedule, the planner, equity and mortgage insurance, the allowance, CSV export — is free. CSV import of payments is free too. Pro adds the import from a photo, screenshot or PDF and shared spaces with other people.

Deleting and the bin

Deleting a loan, a payment or a rate change moves it to Recently deleted for 30 days. A loan comes back with exactly the payments and rate changes deleted together with it. After 30 days rows are erased for good.

Example data

A new account opens on an example household — a 30-year mortgage with escrow, PMI and a few extra payments, a car loan with daily interest and one late payment, and a variable-rate home equity line with a second draw — so every feature shows something. The example disappears the moment you add your own loan, or with Clear example.

What the tracker does not do

It does not look for new deals or remortgage offers — it tells you when your fix ends and checks an offer you enter.
It does not connect to your bank or your lender. Balances come from what you enter or import from a statement; a statement balance keeps the tracker in line with the bank.
It does not decide whether interest is tax-deductible or file anything — it gives you the interest per year.
It is not a loan offer: the refinance check compares the numbers you type with your current loan.
It does not make payments.