Dollars to Pesos (USD to MXN)

You need to know how many pesos your dollars will buy, and you need it before you hand over cash or tap a card. The answer is never the rate on Google. It is the effective rate you actually get after every spread, fee, and hidden charge, and that number can be 3% to 7% worse than the mid-market rate you see online. The conversion is a simple multiplication once you know the true rate, but finding that true rate is the entire game.

Use the calculator in USD to MXN mode, but understand what it shows you. It uses a mid-market rate, which is the theoretical interbank rate, not the rate any bank or ATM will give you. The Federal Reserve H.10 foreign exchange rates give you the official daily benchmark, but even that is a reference, not a promise. Your bank's rate will be worse, and the ATM operator's rate will be worse still. The calculator is a starting point for planning, not a promise of what you will receive.

USD	MXN (at 20.00)
$1	20.00
$5	100.00
$10	200.00
$25	500.00
$50	1,000.00
$100	2,000.00
$250	5,000.00
$500	10,000.00
$1,000	20,000.00
$5,000	100,000.00
$10,000	200,000.00

To convert dollars to pesos, multiply the dollar amount by the exchange rate. For example, $100 at 20 pesos per dollar is 2,000 pesos. This is the correct operation because the peso is the variable you want to isolate. When you see a price in pesos and you want to know the dollar cost, divide the peso amount by the rate. The failure mode here is confusion about which rate to use: the buy rate, the sell rate, or the mid-market rate. The mid-market rate is a benchmark, not a consumer rate, so never use it for your actual conversion math.

When you walk into a casa de cambio in Mexico, you will see two rates: the buy rate and the sell rate. The buy rate is what the exchange house will pay you for your dollars, and the sell rate is what you will pay them for pesos. The difference between these two is the spread, and it is how the exchange makes its money. The mid-market rate sits between them, and the spread can be 2% to 5% depending on the house. Check the sell rate for pesos, because that is the one that applies when you convert dollars to pesos. If you are converting the other way, the buy rate is what you get. Never accept the first rate you see; compare at least two exchanges or use a known bank rate.

When you send money from the US to Mexico, the advertised fee is only half the story. The other half is the exchange rate spread the service applies to your transfer. A service that charges $5 and gives you a rate 2% below mid-market is often worse than a service that charges $10 and gives you a rate 0.5% below mid-market. Calculate the effective exchange rate by dividing the total amount received in pesos by the total amount you paid in dollars, including all fees. The CFPB remittance transfer rule requires the provider to disclose the exchange rate and fees before you confirm the transfer, so use that disclosure to compare apples to apples. The effective exchange rate is the only number that matters, not the fee alone.

The answer to how many pesos is a dollar depends entirely on where and how you convert. The official reference rate from Banxico, called the FIX rate, is published daily at 10:00 AM Mexico City time. The Federal Reserve H.10 series gives you the official US government rate. But if you use an ATM in Mexico, you will get the Visa or Mastercard network rate plus the ATM operator's spread, which is often 1% to 3% plus a fixed fee. If you use a credit card without a foreign transaction fee, you still get the network rate, but the card issuer may add its own spread. Dynamic Currency Conversion, or DCC, is the trap: it offers to show you the charge in dollars, but the conversion rate is 3% to 7% worse than the network rate. Always choose to be charged in the local currency, in this case pesos.

The biggest mistake travelers make is accepting the ATM's offer to convert for you. When the ATM asks if you want to be charged in USD or MXN, always pick MXN. This is because the ATM's conversion rate is a poor one, often 3% to 5% worse than the network rate. The ATM operator's fee is separate and must be disclosed under Banxico's rules, but the spread is hidden. To find the best rate, use an ATM that does not charge a fee, but these are rare and change. The practical move is to use a travel card with no foreign transaction fee, withdraw a larger amount once to minimize the fixed fee, and decline DCC every single time. If the ATM is out of service or the network is down, find another ATM, because the cost of the wrong choice is not worth the convenience.

A credit card that advertises no foreign transaction fee is not giving you the mid-market rate. The card network, Visa or Mastercard, sets a rate that is usually 0.5% to 1% above the interbank rate, and the issuer may add its own margin. The claimed zero fee is real, but the spread is not. To calculate the effective exchange rate, look at the transaction in your statement in USD and divide by the amount in pesos charged. This is the only honest number. If you are buying from a Mexican merchant online, the same rules apply, and you may be offered DCC at checkout. Decline it. The merchant's bank is not doing you a favor; they are making money on the spread.

When you send money to family in Mexico, the fee is what you see, but the spread is what you do not. A service that advertises a low fee may compensate by offering a worse exchange rate. […] The difference between a good and bad effective rate on a $300 transfer can be $10 to $20, which is more than most fees. If you send money regularly, a service with a slightly higher fee but a much better rate will save you money every time. The mid-market rate is the benchmark, and you should never pay more than 2% above it for a remittance.

When you buy from a Mexican merchant online, the checkout page may ask if you want to pay in USD or MXN. […] The merchant's bank sets the DCC rate, and it is almost always a bad deal. The practical rule is to always choose the local currency, MXN, for the transaction. If the merchant does not offer a choice, they are likely forcing DCC, and you should consider another merchant. The effective exchange rate is the only number that tells you what you actually paid.

The Argentine peso is not a single currency for conversion purposes. There is the official rate, which is set by the central bank, and the blue rate, which is the parallel market rate. The blue rate is illegal and not available for card transactions, so if you are a traveler, you get the official rate plus taxes. The PAIS tax and other levies can add 30% to 65% to the cost of a card transaction, depending on the current rules. […] If you are sending money to Argentina, the official rate applies, but the recipient may prefer the blue rate. This is a complex situation, and the only reliable advice is to check the current tax rates and use a card that does not add its own spread. The official rate is not the rate you get.