# Real Effective Exchange Rate (REER): Definition, Formula, and Importance

## What Is the Real Effective Exchange Rate (REER)?

The real effective exchange rate (REER) is the [weighted average](https://www.investopedia.com/terms/w/weightedaverage.asp) of a country's currency in relation to an index or basket of other major currencies. The weights are determined by comparing the relative trade balance of a country's currency against that of each country in the index.

A rise in a country's REER shows that its exports cost more, and its imports cost less, which reduces trade competitiveness.

### Key Takeaways

*   The Real Effective Exchange Rate (REER) is a measure of a country's currency strength compared to a basket of foreign currencies, taking inflation into account to reflect real purchasing power.  
    
*   An increase in REER signifies a loss in trade competitiveness, as it indicates that a country's exports become more expensive while imports become cheaper.  
    
*   To calculate REER, the currency's bilateral exchange rates with major trading partners are averaged, weighted according to their share in trade, then adjusted for inflation.  
    
*   While beneficial for assessing trade competitiveness, REER does not account for non-trade impacts, such as domestic price changes and monetary policy shifts, that could also influence exchange rates.

![Real Effective Exchange Rate (REER)](https://www.investopedia.com/thmb/VzuBuCCrIKo7k7EXHFYEfao2rPA=/1500x0/filters:no_upscale():max_bytes(150000):strip_icc()/reer.asp-final-07492b098b924446b294d0bf41310480.png)

*— Investopedia / Laura Porter*

## Calculating the Real Effective Exchange Rate (REER)

A nation's currency may be considered undervalued, overvalued, or in [equilibrium](https://www.investopedia.com/terms/e/equilibrium.asp#:~:text=Equilibrium%20is%20the%20state%20in,a%20result%20prices%20become%20stable.&text=The%20balancing%20effect%20of%20supply,in%20a%20state%20of%20equilibrium.) with those of other nations that it trades with. A state of equilibrium means that demand and supply are equally balanced and prices will remain stable.

A country's REER measures how well that equilibrium is being held.

REER is determined by taking the average of the bilateral exchange rates between one nation and its trading partners and then weighting it to take into account the trade allocation of each partner.

> **Tip**
>
> The Bank for International Settlements website provides updated effective exchange rate indices on a daily and monthly basis.

### The Formula for REER Is

$\begin{aligned} &\text{REER}=\text{CER}^n\times\text{CER}^n\times\text{CER}^n\times100\\ &\textbf{where:}\\ &\text{CER = Country exchange rate}\\ \end{aligned}$

Breaking down the formula:

*   The average of the exchange rates is calculated after assigning the weightings for each rate. For example, if a currency had a 60% weighting, the exchange rate would be raised to the power by 0.60. The same is done for each exchange rate and its respective weighting.
*   Multiply all of the exchange rates.
*   Then multiply the final result by 100 to create the scale or index.

Some calculations use bilateral exchange rates while other models use real exchange rates. The latter adjusts the exchange rate for inflation.

Regardless of the way in which REER is calculated, it is an average that indicates when a currency is [overvalued](https://www.investopedia.com/terms/o/overvalued.asp) in relation to one trading partner or [undervalued](https://www.investopedia.com/terms/u/undervalued.asp) in relation to another partner.

## Understanding the Insights of REER

A country's REER is crucial for evaluating its trade abilities. REER helps measure a currency's fair value, checks trade factors, and analyzes how competition and technology affect trade indices.

If the U.S. dollar weakens against the euro, U.S. exports to Europe get cheaper. European businesses or consumers buying U.S. goods need to convert their euros to dollars to buy our exports. If the dollar is weaker than the euro, it means Europeans can get more dollars for each euro. As a result, U.S. goods get cheaper due solely to the exchange rate between the euro and the U.S. dollar.

The U.S. trades a lot with Europe. Therefore, the euro to U.S. dollar rate would carry more weight in the index. A big move in the euro exchange rate would impact the REER more than if another currency with a smaller weighting strengthened or weakened against the dollar.

## An Example of Real Effective Exchange Rate in Action

Let's say the U.S. had a foreign trading relationship with only three parties: the eurozone, Great Britain, and Australia. That means the U.S. dollar has a trading relationship with the euro, the British pound, and the Australian dollar.

In this hypothetical example, the U.S. does 70% of its trading with the eurozone, 20% with Great Britain, and 10% with Australia. The basket of currencies in this case would also hold the same percentages, with the euro at 70%, the British pound at 20%, and the Australian dollar at 20%.

A move in the euro would have a greater impact on the basket than a move in the Australian dollar. If one of the exchange rates moved significantly but the weighted average of the basket didn't change, it could mean that the other currencies moved in the opposite direction, offsetting the move of the first currency.

## Comparing REER and Spot Exchange Rates

A spot exchange rate is the current price to exchange one currency for another for delivery on the earliest possible value date. (The [value date](https://www.investopedia.com/terms/v/valuedate.asp) is the effective date for a financial transaction involving an asset that fluctuates in price.)

 Although the spot exchange rate is for delivery on the earliest date, the standard [settlement date](https://www.investopedia.com/terms/s/settlementdate.asp) for most spot transactions is two business days after the transaction date.

The spot exchange rate, therefore, is a current market price. The REER is an indicator of the value of a currency in relation to its trading partners.

## Recognizing the Limitations of REER

[Factors besides trade can impact](https://www.investopedia.com/articles/forex/053115/understand-indirect-effects-exchange-rates.asp) the REER. The real effective exchange rate doesn't take into account price changes, tariffs, or other factors that may affect trade between nations. If prices are higher in one country compared with another, the trade might decrease in the country with higher prices, impacting its REER. The weighting used in the REER calculation then has to be adjusted to reflect any changes in trade.

Also, a country's central bank adjusts monetary policy, changing interest rates up or down. Money flow might rise to countries with higher rates, strengthening their exchange rate, as investors seek returns. The REER would be impacted, but it would have little to do with trade and more to do with the interest rate markets.

> **Fast Fact**
>
> Economists use REER to evaluate a country's trade flow and analyze the impact that factors such as competition and technological changes are having on a country and its economy.

## How Do You Calculate Real Effective Exchange Rate?

First, weigh each nation's exchange rate to reflect its share of the home country's foreign trade. Multiply all of the weighted exchange rates. Then multiply the total by 100.

## What Is the Difference Between Real Exchange Rate and Real Effective Exchange Rate?

The real exchange rate is the current price businesses and consumers will pay to buy a foreign product using their home currencies. For example, if the current U.S. exchange rate between the U.S. and Britain was $138 U.S. dollars for one pound, an American consumer would need $1.38 to buy one pound worth of goods.

When Americans exchange dollars for pounds, the amount they receive is based on the real exchange rate.

## What Is the Difference Between NEER and REER?

The [nominal effective exchange rate](https://www.investopedia.com/terms/n/neer.asp) (NEER) and the real effective exchange rate (REER) are both indicators of a nation's competitiveness in relation to its trading partners.

NEER is the average rate at which one nation's currency is valued in comparison with a basket of other currencies, weighted for the percentage of trade that each currency represents to that nation.

The NEER can be adjusted to compensate for the inflation rate in the home country. That adjusted number is the REER.

## What Does a High REER Mean?

An increase in a nation's REER means businesses and consumers have to pay more for the products they export, while they are paying less for the imported products. It is losing its trade competitiveness.

## The Bottom Line

The real effective exchange rate (REER) is a measure of the relative strength of a nation's currency in comparison with those of the nations it trades with. It is used to judge whether the nation's currency is undervalued, overvalued, or fairly valued.

> **Article Sources**
>
> 1.  Bank for International Settlements. "[Effective exchange rate indices](https://www.bis.org/statistics/eer.htm)."
>     
> 2.  International Monetary Fund. "[What is real effective exchange rate?](https://datahelp.imf.org/knowledgebase/articles/537472-what-is-real-effective-exchange-rate-reer)"