On a fixed-rate term deposit (plazo fijo in Argentina), interest is the amount times the TNA times the days in the term, divided by 365. With $1,000,000 for 30 days at an assumed 30% TNA, you earn $24,658. The TEA is higher because it assumes rolling over principal and interest for a year. Each bank sets its rate.
The bank or wallet shows you a TNA, a term and sometimes what you'll get. This calculator does that maths with the rate you're offered, and adds what you rarely see side by side: the effective monthly rate, to compare with inflation, and the TEA if you roll it over for a whole year. It has no rate built in: you enter it.
The calculator
Enter the TNA you're offered to see what you get at maturity.
Educational tool. The result depends on the rate you enter, excludes taxes and fees, and is not financial advice nor an investment recommendation.
How it's calculated
The TNA (tasa nominal anual, nominal annual rate) is a simple rate expressed per year. For a term of d days, the rate for the term is TNA × d ÷ 365, and the interest is the amount times that rate. It's the same 365-day basis Argentina's central bank (BCRA) uses to compute the 30-day fixed-term rate in its statistical series.
Worked example. Suppose $1,000,000 for 30 days at a 30% TNA. The rate for the term is 30% × 30 ÷ 365 = 2.47%. Interest is $24,658 and at maturity you get $1,024,658.
The TEA (tasa efectiva anual, effective annual rate) assumes that at maturity you roll over principal plus interest, for the same term and at the same rate, for a year: (1 + rate for the term) to the power of (365 ÷ d), minus 1. In the example the TEA is 34.5%, and after a year the $1,000,000 would grow to about $1,344,956. In practice the rate changes at every rollover, so it's a reference, not a promise.
The TEM (effective monthly rate) is the one to put next to monthly inflation: if the month's inflation is higher than the TEM, the deposit loses purchasing power even though it earns. The inflation calculator makes that comparison.
Where to get the TNA
Each bank sets its TNA and it changes often, which is why the calculator doesn't include one. When you set up the deposit, the bank or wallet shows it. To compare across banks, the BCRA publishes a comparator of online peso fixed-term deposit rates, with the TNA banks report.
- Always compare like for like: a 30-day TNA and a 90-day TNA aren't directly comparable; the TEA is.
- The calculator is for fixed-rate deposits. Inflation-linked (UVA) deposits work differently: they pay inflation plus a rate.
- The result doesn't deduct taxes or fees, if any apply.
Frequently asked questions
How is interest on a fixed-term deposit calculated?
Amount × TNA × days ÷ 365. For example, $1,000,000 for 30 days at a 30% TNA earns $24,658 in interest. The TNA is the one the bank offers when you set it up.
What's the difference between TNA and TEA?
The TNA is a simple annual rate: it doesn't account for interest being reinvested. The TEA does: it assumes rolling over principal plus interest for a year, which is why it's always higher than the TNA on a deposit of less than a year.
Does the calculator tell me whether a fixed-term deposit is a good idea?
No. It does the maths with the rate you enter. To see whether it beats inflation, compare the TEM with the monthly inflation you expect, or use the inflation calculator.
Does it work for a UVA deposit?
No. UVA deposits adjust the principal for inflation and add a rate on top; this calculator is for traditional fixed-rate deposits.
Why doesn't the calculator include today's rate?
Because each bank has its own and it changes often: any rate written here would read as the current one and go stale. You'll see it when you set up the deposit, or in the BCRA comparator.
Educational content. Not an investment recommendation nor personalised financial advice: before deciding, check official sources or consult a licensed professional.
Sources and review date
Checked on October 14, 2026. External figures change: if you're deciding based on this, it's worth confirming the number at the source.