Inflation-Indexed Loan Calculator (UVA, UDI, UF, UVR-Style Loans)
Simulate a loan indexed to inflation — like UVA, UDI, UF or UVR mortgages — with a real interest rate: the first and last payment, the nominal balance over time, when it peaks and how the payment compares with your income.
How it works
Payment in index units A = P × i ÷ (1 − (1 + i)⁻ⁿ), i = real rate ÷ 12 · index after k months = (1 + inflation)^(k/12) · nominal payment = A × index · nominal balance = real balance × index · income in year y = income × (1 + growth)^(y − 1)
In an inflation-indexed loan the debt is denominated in an index unit — Argentina’s UVA, Mexico’s UDI, Chile’s UF, Colombia’s UVR — that rises with consumer prices, and you pay a low real rate on top. The payment is constant in real terms but grows in money terms with inflation, and early on the nominal balance can grow even while you pay. The key risk is your income: if wages rise more slowly than prices, the payment takes a larger share of income every year. Compare the first and last payment-to-income ratios and test a pessimistic wage scenario.
Worked example
A 100,000 loan indexed to inflation at a 5% real rate over 20 years has a constant real payment of 659.96 in today’s money. With 25% annual inflation the first monthly payment is 672.34 and it grows every month, reaching 57,242.04 by the last one; the nominal balance keeps rising until month 191, peaking near 1.02 million, and only drops below the original 100,000 in month 239. If income starts at 5,000 and grows 22% a year, the payment takes 13.4% of income at first but 26.2% at the end.
Sources: Wikipedia — Unidad de Fomento · Wikipedia — Inflation-indexed bond
Frequently asked questions
Why does my balance go up even though I pay every month?
Because the debt is adjusted by inflation. Early payments repay little real principal, so the indexation adds more in money terms than you repay; the nominal balance peaks and then falls.
Are indexed loans cheaper than fixed-rate loans?
Their real rate is lower and the first payment is much smaller, which makes them easier to qualify for. Over the life of the loan they cost about the same in real terms as a fixed loan at the matching nominal rate — the difference is who carries the inflation risk: you.
What happens if wages fall behind inflation?
The payment-to-income ratio climbs. Some indexed mortgages include a clause letting you extend the term if the payment exceeds a set share of wages; check your contract.
Does this calculator use real UVA/UDI/UF values?
No — it uses your inflation assumption, so it works for any index and country. Plug in official projections or try several scenarios.
Related calculators
Estimates for education and planning, not financial advice. Lenders’ contracts, fees, day-count and rounding rules differ — check the official cost disclosure (APR / TAE / CAT) in your loan or card agreement before deciding.