Home Loan Calculator

A home loan is the largest instalment most households ever sign, and its two decisions — how much, and over how long — hide inside one monthly payment. Enter the loan, the rate and the term, and this calculator returns the payment, the total interest, and the same loan priced on a 15-year term for the comparison that matters.

The Payment Is a Compromise Wearing a Number

The home loan's formula is the level-payment amortization shared across this hub — M = P × r ÷ (1 − (1 + r)⁻ⁿ) — but a home loan is not a generic loan at larger scale: it is secured on the roof itself, stretched across a working life, and sized against a household's income by underwriting ratios that turn the calculator's output into a gate. This page therefore prices two things the generic instalment pages do not: the term fork, computed live on every run (the same loan at 15 years beside your chosen term, payment and interest both), and the income implication the widget's note states. The reason is the decision's asymmetry — the amount is mostly chosen by the house the family needs, but the term is chosen by the spreadsheet they bring to it, and the term is where the money is: on typical rates, stretching from 15 to 30 years cuts the payment by roughly a quarter while more than doubling the interest. A calculator that prints the fork on every run makes the trade impossible to sign unexamined.

Worked Example: $350,000 at 6.25%

The defaults: over 30 years the payment is $2,155.01 and the total interest $425,804 — more, by itself, than the amount borrowed. Over 15 years the same loan costs $3,000.98 a month — $846 more — but total interest falls to $190,176, a saving of about $235,628. Hold the two rows side by side and the home-loan decision is fully priced: the 30-year term rents flexibility at roughly $236,000 across the loan's life, or about $650 a month of lifetime cost for $846 a month of present relief — a trade some households should take (irregular incomes, other debts at higher rates, investment opportunities with honest edges) and many take unknowingly. The calculator's note adds the underwriting lens: at the 28% housing ratio, the $2,155 payment alone implies a gross household income near $92,000, before the escrow items push the true requirement higher.

The Rate Lock's Small Print

Between application and closing sits the rate lock — the lender's promise to hold a rate for 30–60 days — and its economics are this calculator's arithmetic in miniature: a longer lock or a lower float-down costs points because the lender is selling insurance against the market's movement, worth pricing against the payment sensitivity the worked example established (a quarter point on the default loan is about $60 a month, $21,000 across the term). Buyers in volatile weeks should run the locked and the worst plausible drifted rate through the page before signing the lock agreement, so the insurance is bought — or declined — at a known price.

The Down Payment's Quiet Arithmetic

The loan amount field conceals the other great lever: the down payment. Every dollar prepaid at purchase is a dollar that never pays 30 years of rent — on the worked example's rate, $10,000 more down removes about $22,170 of lifetime payments ($61.57 a month of payment, $12,170 of it interest) — and crossing the 20% threshold additionally deletes PMI, the insurance premium the PITI page prices separately. Against this stands the opportunity cost and the liquidity argument (a house-rich, cash-poor household is one roof-repair from card debt), which is why the down payment is a balance-sheet decision and not a maximisation. The calculator's role: re-run it at the loan amounts your candidate down payments imply, and read the interest column — the down payment's return, stated in the only currency the loan accepts.

Refinancing the Home Loan: The Same Page, Later

Every refinance offer is this calculator asking to be run twice: the remaining balance at the offered new rate and term against the current loan's remaining schedule, with closing costs added to the new loan's interest column before the comparison is legal. The recurring con is the term reset — a fresh 30 years lowers the payment while quietly re-front-loading the interest the amortization page anatomises, so a borrower can "save" monthly and lose six figures lifetime, repeatedly, one refinance every few years. The defences are habits this hub teaches in sequence: price the new loan's TOTAL interest here, compare it with the remaining interest on the old (the amortization page's totals run forward), and let the payment fall where it may. A refinance that survives both pages is a bargain; most advertised ones survive only the first.

Related Tools

More from the Finance Calculators hub: the Mortgage Calculator with Taxes and Insurance — this payment with its escrow entourage — and the Mortgage Amortization Calculator, for the year-by-year shape of the balance.

Frequently Asked Questions

How is a home loan different from a mortgage calculator?

The mathematics is identical — the terms name the same instrument from different sides (the loan is the money; the mortgage is the security pledge over the home). This page's distinct job within the hub is the decision framing: the live 15-versus-your-term comparison and the income-ratio note, aimed at the shopping stage. The hub's mortgage pages then take over — PITI for the fused monthly truth, amortization for the balance's shape — a division of labour across the borrowing journey rather than three copies of one formula, each page stating its siblings' roles so the reader lands where their question lives.

What term should I choose?

The one whose payment survives your worst plausible year, at a total interest you have seen and accepted — which is why the calculator refuses to print one without the other. Households with stable incomes and no better use for the difference usually find the 15-year's $235,628-scale saving decisive; households buying flexibility against volatile incomes are purchasing something real with the 30-year's premium. A middle path the calculator prices indirectly: take the 30-year term and pay it at the 15-year amount voluntarily — the interest outcome approaches the 15-year's, with the contractual payment still low for bad months, at the price of discipline the contract would have supplied.

How much income do I need for this loan?

Lenders start from ratios: housing costs near 28% of gross income, all debts near 36–43% depending on the programme. The calculator's note runs the first ratio on the payment alone (the worked example implies about $92,000); the PITI page's fused figure is the honest numerator, and adding car loans and card minimums approaches the second ratio's territory. Treat the ratios as the lender's risk appetite rather than your family's budget: a household with no other debts, real savings and stable work can carry ratios that would sink a leveraged one, and the calculator prices the loan — the underwriting of your life remains yours.

Does the rate or the amount matter more?

Run both experiments on the calculator: 10% more loan raises the payment and interest by exactly 10% (the formula is linear in P), while one point more of rate on the worked example raises the payment by about $233 and the lifetime interest by about $84,000 — on this scale, a point of rate is worth roughly $38,000 of principal. That asymmetry is why rate-shopping and credit-score repair before purchase outperform haggling over the last increments of price, and why a buydown's value is computable here in two runs: the points' cost against the new rate's lifetime saving, with the break-even a division away.

What is the total cost of the home, honestly?

Assemble it from the hub: price, plus this page's total interest, plus the PITI page's taxes and insurance across the years you will hold them, plus PMI if it applies, minus nothing for the tax deductions without checking your filing actually itemises. On the worked example, interest alone adds $425,804 to a $350,000 loan on a home bought for perhaps $437,500 — the "true price" genre of headline — against which the honest counterweights are the rent not paid across those decades and the appreciation the leverage amplifies. The calculator supplies the largest single term of that ledger with its assumptions printed; the rest of the ledger is the household's own chapter.

What changes if rates are adjustable?

The calculator prices the rate it is given for the whole term — for an adjustable loan that is a scenario, not a forecast: the opening rate holds for its fixed window (2, 5, 7 or 10 years in the common structures), then resets to an index plus margin within stated caps. The honest use is three runs — the teaser rate, the fully-indexed rate, and the worst-case cap path's early years — treating the loan as three candidate loans and underwriting the household against the worst it can afford. Borrowers who ran the third scenario before 2022's resets kept their homes; the calculator cannot forecast the index, and declines, here in writing, to pretend that the first scenario is the loan.

Can I pay the loan off early?

Usually yes — most modern home loans carry no prepayment penalty (check the note's terms; some programmes and jurisdictions differ) — and the amortization page quantifies what extra principal does to the interest total. The strategic question is comparative: retiring 6.25% debt is a guaranteed 6.25% after-tax return, which beats cash and rivals cautious investments, but loses to liquidity when the household's buffer is thin. The calculator frames the fork with its two numbers; the household's emergency fund, job stability and other debts cast the votes.