Loan Comparison — A vs B (Extra Payments & Early Payoff)

Friendly side-by-side comparison. Add extra payments to see months saved and interest saved. Private — runs entirely in your browser.

General

Tip: keep amounts realistic and APR as an annual percentage (e.g., 6.5). Extra payments are applied directly to principal.

Loan A

Extra payments (optional)

Extras reduce principal immediately; last payment is adjusted if needed.

Loan B

Extra payments (optional)

Extras reduce principal immediately; last payment is adjusted if needed.

How this comparison works

  • Standard monthly payment uses the amortizing loan formula with monthly compounding.
  • Extra payments (monthly, one-time, annual) reduce principal immediately, lowering future interest and shortening the term.
  • Payoff time is the month when the balance first reaches zero; the last payment is prorated.
  • Interest saved compares “with extras” to the baseline schedule (no extras).

Edge cases: APR 0% → payment is principal divided by months. Extremely large extras can pay off the loan fast; we end the schedule when balance ≤ 0.

How to Compare Two Loans (A vs B) — With Extra Payments & Early Payoff

Comparing loans is more than checking the APR. Two offers with similar interest rates can behave very differently once you account for term length, fees, and any extra payments you plan to make. This tool shows both the standard amortization (no extras) and the accelerated schedule (with your extra monthly, one-time, or annual payments) so you can make a clear, apples-to-apples decision.

What to look at first

  • Standard monthly payment: Lower isn’t always cheaper; longer terms spread cost.
  • Total interest paid: Best “true cost” metric. Add fees for an even cleaner comparison.
  • Payoff time (with extras): When the balance reaches zero using your extras.
  • Interest saved vs baseline: Interest eliminated by your overpayments.

How extra payments change the math

Amortizing loans charge interest on the remaining principal. Every extra you pay early reduces that principal, shrinking next month’s interest so more of each future payment goes to principal — a compounding effect.

Step-by-step comparison

  1. Enter principal, APR, and term for each loan. Optionally add fees to principal for conservative comparisons.
  2. Choose extra-payment plan: monthly, annual, and/or a one-time lump sum.
  3. Click Compare and review payoff speed, total interest, and interest saved.
  4. Check the balance chart — the steeper drop usually wins.
  5. Use CSV export to review payments line-by-line.

Tips

  • Prepayment rules: Some lenders cap or penalize overpayments — verify first.
  • Term vs APR: Slightly higher APR with a shorter term can still be cheaper overall.
  • Strategy: Small, steady monthly extras are often easiest to sustain.
  • Refinance checkpoints: If rates drop, rerun with a shorter term.

5 Fun Facts about Comparing Loans

APR alone can mislead

A 0.25% lower APR can still cost more if the term is longer—total interest is the real scoreboard.

True cost

Fees act like hidden rate

Roll a £1,000 fee into a £200k loan and it silently bumps the effective rate. Tables reveal the drag.

Fee gravity

Extra payments snowball

£100/month extra on a 25-year loan can wipe years off both loans—often a bigger lever than chasing tiny APR differences.

Prepay edge

Balance curves tell the story

The steeper downward line usually wins. Side-by-side charts make “faster payoff” visible at a glance.

Visual check

Biweekly magic is just math

26 half-payments per year = 13 full payments. It’s a sneaky extra payment that speeds payoff without changing the rate.

Timing hack

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