Irish Calculators
Loans & mortgages

Car Loan Refinance Cost Comparison Calculator

See whether a refinance quote changes both the payment and the cost of your existing car debt. A lower payment can come from extending the term rather than reducing total cost.

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Your numbers

€
Use the principal owed before the next interest period.
Your figures stay on this device.

How the calculation works

A refinance comparison must account for the balance still owed, not only the size of the new instalment. This calculator compares existing and replacement loans at one common horizon, with refinancing fees paid separately upfront.

For each loan add payments made through the same horizon and the remaining principal. Add refinancing fees to the new scenario. Compare full-term interest separately.

  1. Build both repayment paths

    Each loan receives its own fixed nominal rate and remaining term. Payments amortize the shared opening principal using equal monthly interest periods.

  2. Compare at the selected date

    For each path, add payments made by the horizon and any principal still outstanding. This treats both loans as if they were settled at that point.

  3. Include the refinance charges

    Upfront fees are added to the new scenario without increasing its principal. The tool also compares full-term interest less fees separately from the common-horizon result.

Worked example: Same loan and a refinance fee

Sample inputs demonstrate the method. They are not a forecast or product offer.

Both example loans have €1,200 principal, zero interest and twelve €100 payments. At six months each has paid €600 and still owes €600. The new loan adds a €50 upfront fee, so the common-horizon saving is negative €50.

Loan balance (€)
1200
Existing nominal annual rate
0
Existing remaining months
12
New nominal annual rate
0
New term in months
12
Refinance and settlement fees paid upfront
50
Comparison horizon in months
6

Expected result

Existing monthly payment
€100.00
New monthly payment
€100.00
Saving over common horizon
-€50.00
Worked example: One month at two rates

Sample inputs demonstrate the method. They are not a forecast or product offer.

Loan balance (€)
1000
Existing nominal annual rate
12
Existing remaining months
1
New nominal annual rate
0
New term in months
1
Refinance and settlement fees paid upfront
2
Comparison horizon in months
1

Expected result

Existing cost including horizon debt
€1,010.00
New cost including horizon debt and fees
€1,002.00
Saving over common horizon
€8.00

Understanding your result

A positive saving over the common horizon favours refinancing on the entered cash figures; a negative saving means the new scenario costs more at that date.

The full-term comparison can differ because it follows each loan to its own end. Read both measures when the replacement term changes substantially.

Questions you might have

Why compare both at the same horizon?

Comparing unequal payment periods alone can hide a large remaining balance on the longer loan.

Choosing the right inputs

Loan balance
Use the current principal being refinanced, not the vehicle purchase price or the original loan amount. The same balance starts both scenarios.
New term in months
Enter the full proposed replacement term. A longer term may reduce the monthly payment while extending the period during which interest is paid.
Comparison horizon in months
Use the same number of months for both choices. This can be earlier than either loan ends; outstanding principal is then included in the comparison.

Common mistakes to avoid

  • Do not compare only monthly instalments when the terms differ.
  • Include known settlement and arrangement costs in fees; the tool does not discover contractual charges or discounted cash-flow opportunity costs.

Assumptions to check

  • A lower monthly payment can result from a longer term and need not mean a lower total cost.

Sources and method

Read our calculation and testing approach.