What is the interbank exchange rate? (2026 guide)

Key Takeaways:

• The interbank exchange rate is the wholesale rate banks use to trade currencies with each other. It is usually the midpoint between the buy price and the sell price.

• Businesses rarely get this rate. Banks and providers add a margin, and the gap between that margin and the interbank rate is your real foreign exchange cost.

• Airwallex prices its FX competitively at 0.4% to 0.6% above the interbank rate, saving you up to 80% on FX fees as compared to traditional banks.

What is the interbank exchange rate? Simply put, it is the rate banks use when they trade currencies with each other. It is also the benchmark behind every exchange rate you see, from a Google search to a bank quote.

But the rate you see isn’t always the rate you get. Banks and providers often add a margin to the exchange rate, which increases the cost of converting money.

This guide explains how the interbank exchange rate works, how it’s calculated and how to check the rate you’re actually paying.

What does the interbank exchange rate mean?

The interbank exchange rate is the rate banks and large financial institutions use when they trade currencies with each other. Think of it as the wholesale price of a currency, before anyone adds a fee or margin.

When two banks trade, each one quotes a buy price and a sell price. The interbank rate is usually the midpoint between those two prices.

Other names for the interbank exchange rate

You may see the same rate called the mid-market rate, the spot rate or the “real” exchange rate. In everyday use, these terms mean much the same thing.

When you search for a currency pair on Google or use an online converter, this is typically the rate you see.

Interbank rate vs mid-market rate

Strictly speaking, banks trade at a buy price and a sell price, so the interbank rate is a small range. The mid-market rate is the single midpoint of that range.

Most converters show the midpoint, so people use the two terms interchangeably. In this guide, we do the same.

Is there one interbank exchange rate?

No. There is no single, agreed rate. Prices differ slightly between banks, and they move with the currency pair and the time of day.

So the rate you see online is a reference point. It shows you where the market is, but it is not a price you can always book.

Not the same as an interbank lending rate

The term “interbank rate” is also used for the interest rate banks charge each other on loans. That is a different thing. This guide is about the exchange rate used to convert one currency into another.

How is the interbank exchange rate calculated?

The interbank exchange rate is commonly estimated using the midpoint between two prices: the bid price and the ask price. Together, these prices show what buyers are willing to pay and what sellers are asking for a currency.

What are the bid and ask prices?

The bid price is the rate at which a bank or market participant is willing to buy a currency. The ask price is the rate at which they're willing to sell it.

The ask price is usually higher than the bid price. The difference between the two is called the bid-ask spread.

These prices change with market conditions, including supply and demand, economic news, inflation and interest rates. Major currency pairs tend to have narrower spreads, while emerging market currencies often have wider spreads that can fluctuate throughout the day.

The interbank exchange rate formula

To calculate the midpoint, add the bid and ask prices, then divide by two:

Interbank exchange rate = (bid price + ask price) ÷ 2

Exchange rates are quoted in currency pairs, such as SGD/USD. The first currency (SGD) is the base currency, while the second (USD) is the quote currency. The rate tells you how much of the quote currency you get for one unit of the base currency.

How to calculate the interbank exchange rate: An example

Suppose the SGD/USD pair has a bid price of 0.7700 and an ask price of 0.7710. These figures are for illustration only, not live exchange rates.

To calculate the interbank exchange rate:

1. Add the bid and ask prices: 0.7700 + 0.7710 = 1.5410.

2. Divide the total by two: 1.5410 ÷ 2 = 0.7705.

The midpoint rate is 0.7705, and the bid-ask spread is 0.0010.

At this rate, S$10,000 would convert to US$7,705 before any additional fees or exchange rate margins. You can use this midpoint as a benchmark when comparing quotes from banks and money transfer providers. The actual rate offered may differ.

Why does the interbank exchange rate change?

The interbank exchange rate changes throughout the day as banks and other market participants buy and sell currencies. The rate you see now may be different an hour later, even for the same currency pair.

What makes the rate move?

Exchange rates respond to changes in the economy and financial markets. Interest rate decisions, inflation figures, trade data and major global events can all affect how traders value a currency. When demand for one currency rises relative to another, its exchange rate can move accordingly.

That’s why last week’s exchange rate may not reflect what you’ll pay today. If you’re planning an international payment, check the latest rate before making the transfer.

Why you may see different rates on different websites

Online currency converters can show slightly different rates for the same currency pair. They may use different data sources or update their rates at different times.

These differences are often small, but they explain why the figures on two websites may not match exactly.

Why do providers’ exchange rates differ from the interbank rate?

The interbank exchange rate is a useful benchmark, but banks and money transfer providers may quote you a different rate. One common reason is that they add a margin to the exchange rate.

Why providers add a margin

Banks and payment providers need to cover the costs of processing currency exchanges, managing currency risk and running their services. They may also earn revenue through the margin between their quoted exchange rate and the underlying market rate.

Why exchange rate margins vary between providers

Each provider sets its own pricing. Some disclose the exchange rate margin as a separate percentage or fee, while others build it into the quoted exchange rate.

As a result, two providers can charge different amounts for the same currency conversion, even when you check their rates at the same time. Comparing their quotes against the interbank rate can help you understand the difference and identify the more cost-effective option.

Looking for a provider with transparent exchange rates? Airwallex charges highly competitive rates of 0.4% to 0.6% above the interbank rate, helping you save up to 80% on FX fees as compared to traditional banks.

What is the difference between the interbank rate and the rate you’re offered?

The interbank rate gives you a benchmark for comparing exchange rates. The rate your bank or money transfer provider offers may be different because it includes a margin. The bigger the gap between the two rates, the less foreign currency you get for your money.

Here’s a quick overview: 

Let’s use the earlier SGD/USD example. At an interbank rate of 0.7705, S$10,000 converts to US$7,705, before fees.

Now suppose your provider offers a rate of 0.7628, which is approximately 1% below the interbank rate. These figures are for illustration only, as actual rates and margins vary by provider. At this rate, your S$10,000 converts to US$7,628.

That’s a difference of US$77. You might not see it listed as a separate fee on your transfer confirmation, because the cost is built into the exchange rate.

If you make this payment every month, the difference adds up quickly. The more you exchange, the more an unfavourable rate can cost you.

Do all providers disclose their exchange rate markup?

Not always. Some banks and money transfer providers show you the exchange rate without explaining how much of it comes from their markup. Others describe their rates as “competitive” but don’t state the margin they add.

This can make it difficult to compare providers. A low transfer fee doesn’t necessarily mean a cheaper conversion if the exchange rate includes a larger markup.

If a provider doesn’t disclose its margin, you can estimate it by comparing the rate you receive with the interbank rate around the time of your transfer (we cover this in the next section).

How can you check the markup you’re paying?

Even if your provider doesn’t disclose its exchange rate markup, you can estimate it by comparing the rate you received with the interbank rate around the time of your transfer. You’ll need your transfer confirmation and a historical exchange rate for the same currency pair.

Step 1: Find your transfer details

Open your bank statement or transfer confirmation. Note the amount you sent, the amount your recipient received, and the date and time of the transfer. If your statement doesn’t show the exchange rate, check your online banking or transfer receipt.

Step 2: Look up the interbank rate

Find the interbank rate for your currency pair on the day you made the transfer. An online currency converter can give you a useful benchmark, but rates change throughout the day, so try to find a rate from around the time of your transaction.

Step 3: Calculate the rate you received

Divide the amount your recipient received by the amount you sent to work out your effective exchange rate.

For example, if you sent S$10,000 and your recipient received US$7,628, your effective rate was:

US$7,628 ÷ S$10,000 = 0.7628

This means you received US$0.7628 for every Singapore dollar you sent.

Step 4: Compare it with the interbank rate

Now compare your effective rate with the interbank rate at the time of your transfer. In our example, the interbank rate was 0.7705.

Subtract your effective rate from the interbank rate, then divide the difference by the interbank rate:

(0.7705 − 0.7628) ÷ 0.7705 × 100 = 1.0%

Your effective rate was approximately 1% below the interbank benchmark.

This difference gives you an estimate of the markup and other costs reflected in the amount your recipient received. It may not represent your provider’s markup alone if intermediary or recipient bank fees were also deducted.

Step 5: Estimate what it costs you over a year

Once you have an estimate of the markup, you can see how much it could cost across your annual payments.

For example, a 1% markup on S$120,000 in annual currency conversions works out to approximately S$1,200. The actual cost will depend on the rates you receive and any additional fees.

This is why comparing exchange rates matters, especially if your business makes frequent or high-value international payments. A small difference in the rate can add up over time.

For a more detailed walkthrough, including an example using a S$100,000 payment, read our guide to hidden bank fees on international payments.

How can your business get closer to the interbank exchange rate?

You generally can’t access the interbank rate directly, but you can reduce the gap between that benchmark and the rate your business pays. Here are a few tips:

Choose providers that disclose their FX margins

Look for providers that clearly state their exchange rate margins or FX fees, such as Airwallex. This makes it easier to understand what you’re paying and compare costs before confirming a transfer.

Compare your provider’s rate with the interbank rate

Before making a payment, check the interbank rate for your currency pair and compare it with the rate your provider offers. Use the method above to estimate the difference as a percentage.

Remember to account for transfer fees as well as the exchange rate margin. A provider with a better exchange rate may not be the cheapest option once all fees are included. For a comparison of money changers, banks and digital platforms, see our guide to currency exchange in Singapore.

Hold foreign currency to avoid unnecessary conversions

If your business receives and makes payments in the same foreign currency, holding a balance in that currency can help you avoid converting money more often than necessary.

For example, if you receive USD from customers and use those funds to pay USD suppliers, you may be able to make both transactions without converting the funds to SGD in between. This can help you avoid two rounds of conversions, and reduce your FX fees.

Our guide to how to avoid international transaction fees covers other ways to manage payment costs, including holding foreign currency balances, choosing the right card and using local payment rails where available.

Why Singapore businesses choose Airwallex for international transfers

For those who regularly make international payments, Airwallex offers a cost-effective, straightforward way to send money overseas.

Here’s how Airwallex can help with international transfers:

• Transparent FX pricing: Airwallex publishes its FX pricing, with an FX margin of 0.4% to 0.6% above the interbank rate. Our competitive rates save you up to 80% on FX fees.

• Transfer to 200+ countries: You can send payments to 200+ countries with Airwallex. 94% of our transfers go through local rails with $0 transfer fees.

• Hold 20+ currencies: Keep funds in multiple currencies and use those balances to pay overseas suppliers without converting to Singapore dollars first.

You can sign up for an Airwallex Business Account fully online. There are no setup fees, monthly fees, or minimum balance requirements on the free Explore plan.

Frequently asked questions (FAQs)

Where can I find the interbank exchange rate?

You can find it on Google, on financial news sites and on online currency converters. Search for your currency pair, such as SGD to USD, and the rate shown is usually the mid-market rate. It is a reference point, not a rate you can always book. Check it close to the time of your payment.

Is the interbank exchange rate the same as the mid-market rate?

In everyday use, yes. Both describe the midpoint between the buy price and the sell price of a currency pair. Strictly speaking, banks trade at a buy price and a sell price, and the mid-market rate sits halfway between them.

Can my business get the interbank exchange rate?

Usually not exactly. Banks and providers add a margin to the rate they quote you, so you pay a little more than the interbank rate. Airwallex converts at 0.4% to 0.6% above interbank, helping you save up to 80% on FX fees as compared to traditional banks.

Why is my bank’s exchange rate different from the interbank rate?

Your bank starts from the interbank rate and adds a margin to cover its costs and profit. Some banks show this margin openly, and others build it into the rate. The gap between the two rates is your markup on the conversion.

How often does the interbank exchange rate change?

It changes continuously while currency markets are trading. News, data releases and shifts in supply and demand all move it. Check the rate on the day of your payment instead of relying on an older figure.

Is the interbank exchange rate the same as an interbank lending rate?

No. The interbank exchange rate is the price of converting one currency into another. An interbank lending rate is the interest rate banks charge each other on loans. The two share a name but measure different things.