Loan Calculators for Every Borrowing Decision

In a fixed-rate amortizing loan, each monthly payment is identical, but the split between interest and principal shifts over time. Interest is calculated on the outstanding balance, which is largest at the start. For a $200,000 30-year mortgage at 6%, month 1's payment of $1,199 includes $1,000 in interest and $199 in principal — only 17% goes to reducing the balance. By month 360, the last payment is $1,199 again, but now $6 is interest and $1,193 is principal. This front-loading is why halfway through a 30-year loan term (year 15), you have not paid off half the balance — you have paid off closer to one-third. It is also why refinancing late in a loan rarely saves money: you reset the amortization clock, pushing interest-heavy payments back to the start.

Two loans with identical monthly payments can have very different true costs if one has fees baked in. The APR is designed to surface this by spreading fees across the loan term. But APR assumes you hold the loan to maturity — most people refinance or sell within 5-10 years, so effective APR for the time you actually hold the loan is higher than quoted. The break-even for paying discount points (prepaid interest in exchange for a lower rate) is typically 3-5 years. If you plan to move sooner, skip the points. For shopping comparable offers, request Loan Estimates from at least three lenders on the same day (rates change daily); the standardized form makes APR comparisons easy. Watch for lender credits that offset fees — these increase the rate but reduce cash-to-close, useful if you are cash-constrained but not if you will hold the loan long term.

Lender DTI limits vary by country. In the US, conforming mortgages typically cap DTI at 43-45%; FHA loans allow up to 50% for strong credit. The UK uses a loan-to-income multiple rather than DTI — typically 4.5x annual income. Canada uses Gross Debt Service (GDS ≤ 32%) and Total Debt Service (TDS ≤ 40%) ratios under stress-tested rates that add 2 percentage points to the contract rate. Australia's APRA-supervised lenders apply a 3-percentage-point stress buffer and informal DTI scrutiny. These differences mean a buyer borrowing the absolute maximum in one market may not qualify in another — and explain why 'affordable' housing payments differ internationally even at the same income. Our calculators let you plug in your local stress-test rate to see qualifying loan size, not just the headline maximum.