RealGuarani
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Methodology

How the comparison works

Nothing on RealGuarani is estimated. Every number you see in the comparison was read, minutes ago, straight from the exchange house's own official site.

Where the rates come from

We currently monitor 24 exchange houses operating in Ciudad del Este. For each one, a dedicated collector (an "adapter") accesses the house's official site — not an aggregator, not a generic market rate — and extracts the buy and sell rate published at that moment.

  • Banco Atlas
  • Banco Basa
  • Banco Familiar
  • Bonanza Cambios
  • Cambios Alberdi
  • Cambios Alberdi (KM4 CDE)
  • Cambios Chaco
  • Cambio Figueredo
  • Cambios Yrendagué
  • Fenix Exchange (Ciudad del Este)
  • Ita Cambios
  • La Moneda Cambios
  • Maxicambios
  • Mundial Cambios
  • Mundial Cambios - CDE Jebai
  • Mundial Cambios - CDE Km 4
  • MyD Cambios
  • Norte Cambios (Ciudad del Este)
  • Oriente Cambios
  • Uno Cambios
  • Uno Cambios - CDE Uniamérica
  • Uno Cambios - CDE Km 4
  • Uno Cambios - CDE (Caja Aux. N° 19)
  • Valor Cambios

This list grows as we validate new sources — see the project's sources section for the full map of houses still under investigation.

Why the rate varies between houses

There's no single "official rate" for the Real in Guaranis — each exchange house sets its own buy and sell price within a market range. The difference between them comes from factors like:

  • Spread and profit margin — the gap between the buy and sell price is how the house makes money.
  • Volume and cash on hand — a house low on Reais in the till may pay less until it restocks.
  • Delivery method — cash pickup, bank transfer, and digital remittance often carry different rates at the same house.
  • Local competition — houses near heavy tourist traffic adjust price more often.

In practice, this means the same amount in Reais can turn into very different amounts of Guaranis depending on where you exchange — and that's exactly the difference the comparison exists to show.

How to use the comparison

  1. Type how many Reais you want to exchange.
  2. Houses appear ranked by buy rate, best to worst — the first on the list is paying the most Guaranis for your Real right now.
  3. Click a house to open its official site, or the WhatsApp icon (when available) to confirm the rate directly with the house before heading over.

Rates change throughout the day. Always confirm the value with the house before closing the deal — the number on the site is the last one read, not a price guarantee.

How much you lose with each payment method

In our data, picking the best exchange house instead of a typical one saves about R$ 8 per R$ 1,000. The real money is lost in how you pay: a Brazilian card carries the bank's spread plus IOF tax, many stores charge more for card payments, and Pix also builds in an exchange margin. The “How much you lose” block on the home page shows this with today's numbers.

Exchange house rates are still read straight from the source. What's estimated in this section are some card and Pix costs, and every estimate is labeled.

The baseline: the best exchange house

Everything is compared with the cheapest path we measure: bring reais and buy dollars at an exchange house in Ciudad del Este. For each house we work out how many dollars R$ 1,000 buys going through guaraníes (the house buys your reais and sells you dollars, at the rates we collect every 15 minutes). The best house is the baseline, with zero loss. The typical house is the median of all of them.

The math

Each payment method becomes an effective rate in reais per dollar. The loss is how much you would have kept by using the baseline:

loss per R$ 1,000 = 1,000 − 1,000 × (best house rate ÷ payment method rate)

Example with the numbers from our 10/14/2026 research: PTAX of 5.0096 and a baseline of R$ 5.10 per dollar. With a Nubank card and no store surcharge, the rate is 5.0096 × 1.04 × 1.035 ≈ 5.39, so the loss is about R$ 54 per R$ 1,000.

Each payment method

  • Brazilian credit card. Rate = PTAX sell × (1 + bank spread) × 1.035 (IOF). Nubank's spread is exactly 4% over PTAX: we divided Nubank's published rate by the same day's PTAX and got 1.0400 on 15 out of 15 business days (09/01 to 10/09/2026). The 6% upper end (Santander) and the other banks' figures come from the press, with no document from the bank.
  • Card with a store surcharge. Many stores charge more for card payments. CDE's biggest shopping guide says “normal is between 5% and 10%”. We add that range on top of the card cost.
  • Pix at the store. Worked out from a Rendimento Pay press release about Crazy Week 2026: an average ticket of US$ 140.10 or R$ 731.36, i.e. R$ 5.22 per dollar, 6.2% to 6.5% above that week's PTAX. It's the average of a single event, and the press still disagrees on the IOF rate for Pix.

ATM withdrawals and being charged in reais at the card terminal (DCC) are left out: we found no reliable fee data for Ciudad del Este.

What's confirmed and what's an estimate

Confirmed: PTAX (Central Bank, re-read every hour), the 3.5% IOF (the decree's text), Nubank's 4% spread (Nubank's open data against PTAX) and the exchange house rates (collected by us). Estimates: other banks' spread (4% to 6%), the store's card surcharge (5% to 10%) and the cost of Pix (PTAX + 6.2% to 6.5%).

About the 3.5% IOF

The rate is set in art. 15-B of Decree 6,306/2007, as worded by Decree 12,499/2025. Congress suspended that decree, but the Supreme Court (STF) restored it in a provisional ruling on 07/16/2025 (ADC 96). As of 10/14/2026 we found no final judgment. In practice, the 3.5% IOF is charged today, but it could change. Articles citing 4.38%, 3.38% or zero IOF in 2028 are out of date.

Sources

Update frequency

A scheduled job fetches new rates every 15 minutes. Houses whose last reading is older than 3 hours automatically drop from the ranking — we'd rather show fewer houses than show a stale price as if it were current.

See the rates nowFrequently asked questions about exchange in Ciudad del Este