Longer term, lower payment, higher cost

Short answer #

A longer term usually lowers the payment by spreading principal. It can materially raise total interest, so compare payment, total payments and remaining balance at the same horizon.

Important variables #

• Effective rate and fees
• Same comparison horizon
• Tax, cost and risk
• Remaining debt or ending wealth

Worked example #

€30,000 at 5% costs roughly €566 monthly over five years or €424 over seven — but interest runs two years longer.

Break-even: What changes the result? #

Test the main driver as a cautious, central and optimistic range. Also check whether the ranking reverses at a crossover or remains robust across the range.

Common mistakes #

• Equating low payment with low cost
• Equating certain interest saving with uncertain return
• Mixing nominal and real values

Sources & assumptions

• European Central Bank — Monetary policy decisions, 23 July 2026 (2026-08-17)
• RATIOXA — Methodology and formulas (2026-08-17)