Loan & mortgage amortisation calculator
Payment, total interest, the first-payment split.
Interactive: loan & mortgage amortisationEasy
The most widely held fixed-income instrument in the world is a mortgage — usually held by the borrower, from the other side. Here is what the schedule actually costs.
- Monthly payment
- —
- Total paid
- —
- Total interest
- —
- First payment is
- —
Standard annuity formula. Note the last line: early payments are almost entirely interest, which is why overpaying in year one saves far more than overpaying in year twenty — and why MBS investors care so much about prepayment.
The idea behind it
This calculator belongs to Fixed Income, where the mechanism it computes is explained step by step, with the formula, what each input means and where the simple model stops being right. Everything is computed in your browser; nothing you type is sent anywhere.
Instruments it applies to
- Floating Rate Note — A bond whose coupon resets with the market — interest-rate risk engineered out, credit risk left in.
- Mortgage-Backed Security — Thousands of home loans bundled into a bond — with the homeowners' right to refinance baked into your risk.
- Asset-Backed Security — Any cash-flowing asset — car loans, credit cards, royalties — sliced into bonds of graded risk.
- CMBS — Securitised loans against offices, malls and hotels. Fewer, larger, lumpier loans than residential — which makes the analysis property-by-property and the tail much thicker.
- Schuldschein — A loan that behaves like a bond and is documented like a handshake — the German middle market's answer to the capital market.
More calculators from Fixed Income
- Bond price, duration & convexity — the full price–yield toolkit.
- Yield-to-maturity solver — from price to yield by bisection.
- Tax-equivalent yield — comparing tax-exempt and taxable bonds.
- Bond ladder planner — rungs, average yield, annual income.
- Accrued interest & dirty price — what you actually pay.
- Real return after inflation — Fisher's equation, exactly.