A loan comparison tool that puts up to three loan offers side by side so you can see, at a glance, which one is genuinely cheaper. For each loan you enter the amount, the interest rate (APR), the term in years and any upfront fees — and the tool instantly works out the monthly payment, the total interest, the total cost (interest plus fees) and the total amount repaid. It then ranks the loans, highlights the cheapest, and draws a remaining-balance chart so you can watch how each loan is paid down over time. It’s for anyone weighing up personal loans, car finance, debt-consolidation offers or competing mortgage deals.
How it works
Each loan is modelled as a standard amortising loan. The fixed monthly payment comes from the amortisation formula:
M = P · r(1+r)ⁿ ⁄ ((1+r)ⁿ − 1)
where P is the amount borrowed, r is the monthly interest rate (annual rate ÷ 12 ÷ 100) and n is the number of months (years × 12). The tool then simulates the loan month by month: it charges interest on the outstanding balance, applies the payment (plus any extra overpayment you enter) to clear principal, and rolls the balance forward until it reaches zero. From that simulation it reads off the total interest paid, adds the upfront fees to get the total cost, and ranks every loan by that total-cost figure — the number that actually decides which offer is the better deal. The line chart plots each loan’s remaining balance against the month, so a loan that clears faster or more cheaply is obvious visually, not just numerically.
Everything runs entirely in your browser. Your loans and chosen currency are saved with
localStorage, so they are still there the next time you open the page, and you can export
the whole comparison to a CSV file for a spreadsheet or a mortgage adviser.
Example
Say a bank offers you £15,000 at 6.9% over 5 years with no fee, while a broker offers £15,000 at 5.5% over 6 years with a £400 arrangement fee. The first looks like the higher rate, but the comparison tells the real story:
| Loan | Amount | Rate | Term | Monthly payment | Total interest | Fees | Total cost |
|---|---|---|---|---|---|---|---|
| Loan A | £15,000 | 6.9% | 5y | ~£296 | ~£2,760 | £0 | ~£2,760 |
| Loan B | £15,000 | 5.5% | 6y | ~£245 | ~£2,640 | £400 | ~£3,040 |
Loan B has the lower monthly payment, but because of the extra year and the £400 fee its total cost is higher. The tool flags Loan A as the cheaper deal overall — exactly the kind of trade-off that’s easy to miss when you only look at the monthly figure. Add a small extra monthly payment to either loan and you’ll see the interest fall and the payoff date move forward.
Every figure is calculated in your browser — no numbers are uploaded or stored.