Mortgage maths, made clear.

Free calculators for mortgages, affordability, refinancing, and more, built to match how lenders in your market actually calculate the numbers.

Most mortgage calculators are built for one country and reused for the rest by swapping the currency symbol.The rules differ in ways that change the arithmetic.

How mortgage rules differ across the six markets Fiscalgrove covers
Market	The rule that changes the maths
Canada	Fixed rates compound semi-annually by law, so a Canadian 5% and an American 5% are not the same payment.
Australia	Borrowers are assessed three percentage points above the rate they will pay, because APRA requires it.
New Zealand	Three separate caps apply, and you can borrow only the lowest of the three.
Ireland	The income multiple is set by the Central Bank rather than by your lender.
United Kingdom	There is no mortgage insurance at all. What you pay instead is a higher rate by loan-to-value band.
United States	PMI applies below 20% down, with two statutory cancellation dates about eleven months apart.

Six different formulas, not six labels. That is why the calculators are grouped by market rather than by topic.

How these numbers are produced

Computed, never copied: Every figure comes from the underlying formula, the same one a lender uses. Nothing is estimated where it can be calculated.
Sourced to the regulator: Tax bands, loan-to-value ceilings, income multiples and serviceability buffers each link to the government or regulator that publishes them.
Dated, and checked: Every statutory value carries the date it was last verified, and a staleness report flags anything overdue. A figure without a date cannot be checked.

What this site is not

Not a broker, a lender, or a regulated adviser. Fiscalgrove does not sell mortgages or pass your details to anyone who does. There is no form and no quote to request. Where a question needs regulated advice, the site says so.

Who builds it

Majid Bilal, a software engineer who spent twelve years implementing statutory payroll calculations across multiple countries, where a wrong rule is a legal problem rather than a bug. More on the about page, and how corrections are handled in the editorial policy.

United KingdomUK calculatorsMortgage repayments, affordability, remortgaging, Stamp Duty (SDLT), LTV, overpayments, offset, and buy-to-let — in £.

All UK calculators →

United StatesUS calculatorsFull PITI mortgage payments, home affordability (28/36 DTI), refinancing, PMI, points, ARM vs fixed, and closing costs — in $.

All US calculators →

CanadaCA calculatorsMortgage payments (semi-annual compounding), GDS/TDS affordability, land transfer tax, CMHC insurance, refinancing, LTV, and rental yield — in $.

All CA calculators →

AustraliaAU calculatorsMortgage repayments, borrowing power, stamp duty, LMI, offset accounts, refinancing, and rental yield — in $.

All AU calculators →

New ZealandNZ calculatorsMortgage repayments, affordability, LVR restrictions, fixed vs floating rates, refinancing, and rental yield — in $.

All NZ calculators →

IrelandIE calculatorsMortgage repayments for Irish home loans — weekly, fortnightly, or monthly, with total interest and a full amortisation schedule, in €.

All IE calculators →

Prefer to read first? Read our blog for plain-English mortgage guides.