Calculateur de Amortization
Estimate monthly payment, total paid, and total interest for an amortizing loan.
Formula and method
This calculator computes Monthly payment, Total interest directly in your browser without sending data to an external server.
Mathematical formula
- Monthly payment:
(() => { const r=rate ÷ 1200, n=years × 12; if(r===0) return principal ÷ n; const p=1+r^(n); return Number.isFinite(p) ? principal × r × p ÷ (p-1) : principal × r; })() - Total interest:
(() => { const r=rate ÷ 1200, n=years × 12; const payment = r===0 ? principal ÷ n : (() => { const p=1+r^(n); return Number.isFinite(p) ? principal × r × p ÷ (p-1) : principal × r; })(); return payment × n-principal; })()
Variables and parameters
- Principal (principal): default value 300000 $.
- APR (rate): default value 6.5 %.
- Years (years): default value 30.
Some formulas are undefined for certain input combinations (such as division by zero or logarithms of non-positive numbers). In those cases the live tool displays an alert instead of NaN.
Embed this tool
Paste this snippet into your own site or blog post to embed a live, working copy of this tool. It links back to the full page on SpecWhale.
Frequently asked questions
What equation and variables does Amortization Calculator use?
Amortization Calculator evaluates outputs such as <strong>Monthly payment, Total interest</strong> based on inputs including Principal, APR, Years. Check the Mathematical Method section for the explicit formula.
How can I compare different financial scenarios using Amortization Calculator?
You can click the "Add to Compare" button after computing your scenario to pin it to your temporary side-by-side Compare Workbench, allowing you to evaluate loan, rate, or interest differences.
What happens if I enter invalid or zero values into Amortization Calculator?
If an input combination is mathematically undefined (such as division by zero or negative square roots), SpecWhale alerts you gracefully rather than returning invalid NaN outputs.
Are my calculations in Amortization Calculator saved or private?
All calculations are 100% private and run locally in your Web browser. Your numbers are never uploaded to any server, but can be saved locally to your device or exported as CSV/JSON.
Is Amortization Calculator free to use?
Yes. Amortization Calculator is completely free, has no usage limit, and does not require an account, email, or API key.
Does Amortization Calculator store or upload my data?
No. Amortization Calculator calculates everything locally in your browser. Nothing you type is sent to a server or stored by SpecWhale.
How accurate is Amortization Calculator?
Amortization Calculator uses a standard formula (see the Method section above for the exact expression). For high-stakes financial, medical, or legal decisions, confirm the result with a professional or an authoritative source before relying on it.
Can I embed Amortization Calculator on my own website?
Yes. Use the "Embed this tool" snippet on this page to add a free, working copy of Amortization Calculator to your own blog post or page.