--- title: Interest Rate Parity | Formula, Example, Analysis, Conclusion, Calculator description: Interest Rate Parity (IRP) helps define the relationship between interest rates, spot rates, and forward rates. Click for more information. --- [![Carbon collective](https://www.carboncollectiveinvesting.com/hubfs/raw_assets/public/CarbonCollective_August2021%20copy/images/carbon-collective-green-investing-logo-white.4f6047d4.svg "Carbon collective")](https://www.carboncollectiveinvesting.com/) - About - Employers - [Sustainable 401(k)](https://www.carboncollectiveinvesting.com/401k) - [401(k) Comparison Tool](https://www.carboncollectiveinvesting.com/401k/plan-comparison-tool) - Individuals - [FAQ](https://www.carboncollective.co/en/knowledge/faqs) - [ETF](https://www.carboncollectivefunds.com/) - Learn - [Sustainable Investing](https://www.carboncollective.co/sustainable-investing) - [Investing Basics](https://www.carboncollective.co/sustainable-investing/investing-basics) - [Blog](https://blog.carboncollective.co/) - [Tools](https://tools.carboncollective.co/calculator/) - Log in - [Carbon Collective](https://app.carboncollective.co) - [Altruist](https://app.altruist.com) [Talk to a human](https://ask.carboncollective.co/f4o5dylkg) [Sign up](https://app.carboncollective.co/sign-up) [Log In](http://app.carboncollective.co/) [![Carbon collective](https://www.carboncollectiveinvesting.com/hubfs/raw_assets/public/CarbonCollective_August2021%20copy/images/carbon-collective-green-investing-logo.53b28bee.svg "Carbon collective")](https://www.carboncollectiveinvesting.com/) - About - Employers - [Sustainable 401(k)](https://www.carboncollectiveinvesting.com/401k) - [401(k) Comparison Tool](https://www.carboncollectiveinvesting.com/401k/plan-comparison-tool) - Individuals - [FAQ](https://www.carboncollective.co/en/knowledge/faqs) - [ETF](https://www.carboncollectivefunds.com/) - Learn - [Sustainable Investing](https://www.carboncollective.co/sustainable-investing) - [Investing Basics](https://www.carboncollective.co/sustainable-investing/investing-basics) - [Blog](https://blog.carboncollective.co/) - [Tools](https://tools.carboncollective.co/calculator/) - Log in - [Carbon Collective](https://app.carboncollective.co) - [Altruist](https://app.altruist.com) [Talk to a human](https://ask.carboncollective.co/f4o5dylkg) [Sign up](https://app.carboncollective.co/sign-up) [Log In](http://app.carboncollective.co/) **[Home](https://www.carboncollectiveinvesting.com/) > [Sustainable Investing](https://www.carboncollectiveinvesting.com/sustainable-investing) >** Interest Rate Parity # Interest Rate Parity ![](https://www.carboncollectiveinvesting.com/hubfs/Brooke%20Tomasetti.png) Written by Brooke Tomasetti | Reviewed by [Subject Matter Experts](https://www.carboncollectiveinvesting.com/subject-matter-experts) Updated on October 1, 2024 Fact Checked Why Trust Carbon Collective? ### Table of Contents Interest rate parity (IRP) is a concept which states that the interest rate differential between two countries is the same as the differential between the forwarding exchange rate and the spot exchange rate. Put simply, the interest rate parity suggests a relationship between interest rates, spot exchange rates, and forward exchange rates—which means investors can be indifferent to interest rates between countries. This essentially means that if the IRP theory is true, then it does not really matter whether an investor converts his money into a foreign currency and invests the same into that foreign country, or invests the money in the home country and then converts the proceeds into the foreign currency, as he would be earning exactly the same amount of money in both the situations. [![Studying for school or work? Don't forget to apply what you learn to your personal finances—Read the Smart Investing 101 Guide.](https://hubspot-no-cache-na2-prod.s3.amazonaws.com/cta/default/20345524/b5d13e91-d1d6-4775-9e39-a7f8ebf9ad7a.png)](https://hubspot-cta-redirect-na2-prod.s3.amazonaws.com/cta/redirect/20345524/b5d13e91-d1d6-4775-9e39-a7f8ebf9ad7a) When the exchange rate risk is ‘covered’ by a forward contract, the condition is called covered interest rate parity. When the exposure to foreign exchange risk is uncovered (when no forward contract exists) and the IRP is to be based on the expected future spot rate, it is called an uncovered interest rate parity. ## Interest Rate Parity Formula ![](https://www.carboncollectiveinvesting.com/hubfs/image-png-Apr-22-2022-06-38-15-86-AM.png) - F0 = Forward Exchange Rate - S0 = Spot Exchange Rate - ia  = Interest rate of country A (quote currency) - ib  = Interest rate of country B (base currency) The spot exchange rate refers to the current exchange rates prevalent between any two countries and the forward exchange rate is the exchange rate between the two currencies at any future point in time. Both spot and forward exchange rates are usually available with financial institutions such as banks and currency dealers. In fact, one can get forward rate quotes between two countries for periods ranging from a week to as long as five years. If the difference between the forward rate and the spot rate is positive, then the currency is said to be trading at a forward premium, but if the difference between the forward rate and the spot rate is negative, then the currency is said to be trading at a forward discount. Normally, the currency with the lower interest rates will trade at a forward premium while the currency with the higher interest rates trades at a forward discount. The interest rate of country A is the interest rate in the foreign country where the investor hopes to invest and the interest rate of Country B is the interest rate in the home country of the investor. ## Interest Rate Parity Example You are provided with the following details. Calculate the forward exchange rate as per the interest rate parity concept. ![](https://www.carboncollectiveinvesting.com/hubfs/image-png-Apr-26-2022-01-43-14-87-AM.png) Using the formula, we can work out the forward rate using the numbers in the table: ![](https://www.carboncollectiveinvesting.com/hubfs/image-png-Apr-22-2022-06-38-45-47-AM.png) Since the difference between the forward exchange rate and the spot exchange rate is negative, it indicates that the dollar is trading at a forward discount as compared to the Euro. Let us illustrate the IRP concept by considering two situations: **Situation 1:**  If an investor were to invest $1000 in a 5% interest-bearing instrument in the United States for one year, and exchange the sum earned into Euros in one year, he would have earned $1050 \[1000+ (1000\*5%)\] in one year. Converting this earned amount of $1050 into Euros would mean using the IRP forward exchange rate of 0.771421. That would earn him 809.992 Euros (1050\* 0.771421) **Situation 2:** Say, the investor decides to convert his $1000 into Euros and invest the money in a 3% interest-bearing instrument in Germany, and exchange the sum earned back into US Dollars after one year. Converting $1000 in the spot exchange rate of 0.7864 would give him 786.4 Euros (1000\*0.7864). When he invests this 786.4 Euros in a 3% interest-bearing instrument in Germany for one year, he will receive the same 809.992 Euros \[786.4 + (786.4\*3%)\] after one year. In essence, if the IRP concept were to hold, the investor would earn the same amount of money in both currencies irrespective of the exchange rates. ## Interest Rate Parity Analysis The IRP concept implies that the concept of arbitrage does not exist which means that investors will not be able to profit from the difference in the interest rates of different currencies. If the IRP concept does not hold up, then it gives opportunities for investors and forex traders to make riskless profits. Continuing with the above example, say the investor locks up his forward contract for the IRP forward exchange rate of 0.771421 (Euro/USD) but the actual forward exchange rate turns out to be 0.7899, which is higher than the locked forward rate of 0.771421. So instead of earning 809.992 Euros (1050\* 0.771421), he would be earning 829.395 Euros (1050\* 0.7899). This basically means the investor can make a profit by exploiting the difference in the forward rates. Despite its importance, IRP comes with its own set of limitations. 1. IRP assumes that [capital](https://www.carboncollectiveinvesting.com/sustainable-investing/capital/) can freely move across countries. 2. The other assumption is that of perfect asset substitutability which essentially means that IRP assumes that domestic and foreign assets can be perfectly substituted for one another. But that is not always the case due to various external risks including [liquidity](https://www.carboncollectiveinvesting.com/sustainable-investing/liquidity/) risks, political risks, costs, and taxation. Despite the limitations, covered interest rate parity holds true in many situations when there is scope for free capital movement and limited capital controls. But uncovered interest rate parity rarely works in real-life situations due to the presence of multiple risk factors. ## Interest Rate Parity Conclusion To sum up: - Interest Rate Parity suggests that the difference in interest rates between two countries is equal to the difference between the forward exchange rate and the spot exchange rate - IRP helps define the relationship between interest rates, spot rates, and forward rates and suggests that there will be no scope for arbitrage in interest rate differentials since the difference in the exchange rates would be reflected as either forward premium or forward discount. - Interest Rate Parity can be either covered interest rate parity or uncovered interest rate parity depending upon the existence or non-existence of a forward contract - IRP is based on assumptions of capital mobility and asset substitutability ## Interest Rate Parity Calculator You can use the interest rate parity calculator below to work out the forward exchange rate and determine if it is trading at a forward premium or a forward discount by entering the required numbers. Spot Exchange Rate Interest Rate A (Quote Currency) Interest Rate B (Base Currency) Forward Exchange Rate ## FAQs ### 1. What is an interest rate parity? Interest rate parity is a market condition in which the difference between the interest rates of two countries is equal to the difference between their forward exchange rates. Interest rate parity also implies that any deviations from this will result in an arbitrage opportunity, allowing investors to make fewer risk profits. ### 2. How do you calculate interest rate parity? Forward Rate A = (Spot Exchange Rate \* Spot Price) / (1 + Interest Rate B) – 1; or Forward Rate A = (Spot Exchange Rate \* Spot Price) / (Interest Rate B – Interest Rate A) ### 3. Why does uncovered interest rate parity rarely work in real-life situations? Uncovered interest rate parity rarely works in real-life situations due to the presence of multiple risk factors, especially liquidity risks and political risks. ### 4. What is the difference between covered and uncovered interest rate parity? Covered interest rate parity is a situation in which there is a forward contract adopted between the two nations, allowing risk-free arbitrage. Uncovered interest rate parity is a lack of adoption of such contracts. ### 5. Why is interest rate parity important? Interest rate parity is important because it signifies the relationship between interest rates, spot rates, and forward rates. It also helps define the relationship between interest rates and exchange rates. ### Related Topics - [Sustainable 401(k) Plan](https://www.carboncollective.co/401k) - [Sustainable Investing](https://www.carboncollective.co/sustainable-investing/) - [Investing Basics](https://www.carboncollective.co/sustainable-investing/investing-basics) - [Retirement Glossary](https://www.carboncollective.co/sustainable-investing/retirement-planning-glossary) - [Best Retirement Plans](https://www.carboncollective.co/sustainable-investing/the-10-best-retirement-plans) - [Wealth Manager Vs Financial Advisor](https://www.carboncollective.co/sustainable-investing/wealth-manager-vs.-financial-advisor) ![Attend Our Next Webinar](https://www.carboncollectiveinvesting.com/hubfs/carbon-collective-green-investing-icon-webinar.12af7b6e.svg) ### Attend Our Next Webinar Join our next Sustainable Investing 101 webinar, get our favorite DIY options, and walk through how we build our portfolios. [Watch Now](https://www.carboncollective.co/sustainable-investing-webinar-green-retirement-month) ![Get Our Newsletter](https://www.carboncollectiveinvesting.com/hubfs/carbon-collective-green-investing-icon-demo.6ed28722.svg) ### Get Our Newsletter Go a level deeper with us and investigate the potential impacts of climate change on investments like your retirement account. Join Newsletter ![close-typeform](data:image/gif;base64,R0lGODlhEQARAIAAAODn7P///yH5BAEHAAEALAAAAAARABEAAAIqBIKpab3v3EMyVHWtWZluf0za0XFNKDJfCq5i5JpomdUxqKLQVmInqyoAADs=) ![Talk To A Human](https://www.carboncollectiveinvesting.com/hubfs/carbon-collective-green-investing-icon-chat.49d48c5b.svg) ### Talk To A Human Joining a new investment service can be intimidating. We’re here for you. Click below to email us a question or book a quick call. [Ask a Question](https://ask.carboncollective.co/f70pooobq) Topics ## Sustainable Investing Topics View our list of some topics below. See More - Portfolios - [Performance](https://www.carboncollectiveinvesting.com/returns) - About - [Sustainable 401(k)](https://www.carboncollectiveinvesting.com/401k) - Learn - [FAQ](https://www.carboncollective.co/en/knowledge/faqs) - [Sustainable Investing](https://www.carboncollective.co/sustainable-investing) - [Investing Basics](https://www.carboncollective.co/sustainable-investing/investing-basics) - Contact - [Contact us](mailto:hello@carboncollective.co) - [Legal](https://www.carboncollective.co/legal) - [Privacy Policy](https://www.carboncollectiveinvesting.com/hubfs/2022-11%20Carbon%20Collective%20Privacy%20Policy.pdf) - [Back to top](https://www.carboncollectiveinvesting.com/sustainable-investing/interest-rate-parity#top-of-page) DISCLAIMERS: Advisory services provided by Carbon Collective Investment LLC (“Carbon Collective"), an SEC-registered investment adviser. A copy of Carbon Collective's current written disclosure statement discussing Carbon Collective’s business operations, services, and fees is available at the SEC’s investment adviser public information website – [www.adviserinfo.sec.gov](https://adviserinfo.sec.gov/firm/summary/310129) or [our legal documents here](https://blog.carboncollective.co/legal-documents/). The articles and research support materials available on this site are educational and are not intended to be investment or tax advice. Carbon Collective does not make any representations or warranties as to the accuracy, timeliness, suitability, completeness, or relevance of any information prepared by any unaffiliated third party, whether linked to Carbon Collective’s web site or incorporated herein, and takes no responsibility therefor. All such information is provided solely for convenience purposes only and all users thereof should be guided accordingly. Investments in securities: Not FDIC Insured • No Bank Guarantee • May Lose Value. Investing in securities involves risks, and there is always the potential of losing money when you invest in securities. Before investing, consider your investment objectives and Carbon Collective's charges and expenses. Carbon Collective's internet-based advisory services are designed to assist clients in achieving discrete financial goals. They are not intended to provide comprehensive tax advice or financial planning with respect to every aspect of a client's financial situation and do not incorporate specific investments that clients hold elsewhere. For more details, see our Form CRS, Form ADV Part 2 and other disclosures. Past performance does not guarantee future results, and the likelihood of investment outcomes are hypothetical in nature. Not an offer, solicitation of an offer, or advice to buy or sell securities in jurisdictions where Carbon Collective is not registered. © 2026 Carbon Collective Corporation. All rights reserved. × #### Fact Checked Carbon Collective partners with financial and climate experts to ensure the accuracy of our content. Our team of reviewers are established professionals with years of experience in areas of personal finance and climate. They have contributed to top tier financial publications, such as Reuters, Axios, Ag Funder News, Bloomberg, Marketwatch, Yahoo! Finance, and many others. This team of experts helps Carbon Collective maintain the highest level of accuracy and professionalism possible. × #### Why Trust Carbon Collective Carbon Collective is the first online investment advisor 100% focused on solving climate change. We believe that sustainable investing is not just an important climate solution, but a smart way to invest. We follow ethical journalism practices, which includes presenting unbiased information and citing reliable, attributed resources. Much of our research comes from leading organizations in the climate space, such as Project Drawdown and the International Energy Agency (IEA). Our goal is to deliver the most understandable and comprehensive explanations of climate and finance topics. Our writing and editorial staff are a team of experts holding advanced financial designations and have written for most major financial media publications. Our work has been directly cited by organizations including MarketWatch, Bloomberg, Axios, TechCrunch, Forbes, NerdWallet, GreenBiz, Reuters, and many others. We strive to empower readers with the most factual and reliable climate finance information possible to help them make informed decisions. } ```json { "@context" : "https://schema.org", "@type" : "Organization", "alternateName" : "Carbon Collective", "contactPoint" : { "@type" : "ContactPoint", "areaServed" : "US", "availableLanguage" : "en", "contactType" : "customer service", "telephone" : "(650) 868-2697" }, "logo" : "https://www.carboncollective.co/hubfs/CarbonCollectiveLogo.png", "name" : "Carbon Collective Investing LLC", "sameAs" : [ "https://www.facebook.com/carboncollectiveinvesting/", "https://twitter.com/carbncollective", "https://www.instagram.com/carbon.collective/", "https://www.youtube.com/channel/UC769Y-F-L_B37kyQfdpvyXA", "https://www.linkedin.com/company/carbon-collective/", "https://www.crunchbase.com/organization/carbon-collective", "https://adviserinfo.sec.gov/firm/summary/310129", "https://www.wikidata.org/wiki/Q110243690" ], "url" : "https://www.carboncollective.co/" } ``` ```json { "@context" : "https://schema.org", "@type" : "FAQPage", "mainEntity" : [ { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "Interest rate parity is a market condition in which the difference between the interest rates of two countries is equal to the difference between their forward exchange rates. Interest rate parity also implies that any deviations from this will result in an arbitrage opportunity, allowing investors to make less risk profits." }, "name" : "What is an interest rate parity?" }, { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "Forward Rate A = (Spot Exchange Rate * Spot Price) / (1 + Interest Rate B) – 1; or Forward Rate A = (Spot Exchange Rate * Spot Price) / (Interest Rate B – Interest Rate A)" }, "name" : "How do you calculate interest rate parity?" }, { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "Uncovered interest rate parity rarely works in real-life situations due to the presence of multiple risk factors, especially liquidity risks and political risks." }, "name" : "Why do uncovered interest rate parity rarely work in real-life situations?" }, { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "Covered interest rate parity is a situation in which there is a forward contract adopted between the two nations, allowing risk-free arbitrage. Uncovered interest rate parity is a lack of adoption of such contracts." }, "name" : "What is the difference between covered and uncovered interest rate parity?" }, { "@type" : "Question", "acceptedAnswer" : { "@type" : "Answer", "text" : "The Interest rate parity is important because it signifies the relationship between interest rates, spot rates and forward rates. It also helps define the relationship between interest rates and exchange rates." }, "name" : "Why is an interest rate parity important?" } ] } ``` ```json { "@context" : "https://schema.org", "@type" : "BlogPosting", "author" : { "@type" : "Person", "name" : "https://20345524.fs1.hubspotusercontent-na1.net/hubfs/20345524/Brooke%20Tomasetti.png", "url" : "https://www.carboncollectiveinvesting.com/sustainable-investing/author/brooke-tomasetti" }, "dateModified" : "2024-10-01", "datePublished" : "2021-03-24", "description" : "Interest Rate Parity (IRP) helps define the relationship between interest rates, spot rates, and forward rates. Click for more information.", "headline" : "Interest Rate Parity | Formula, Example, Analysis, Conclusion, Calculator", "image" : "", "mainEntityOfPage" : { "@id" : "https://www.carboncollectiveinvesting.com/sustainable-investing/interest-rate-parity", "@type" : "WebPage" }, "publisher" : { "@type" : "Organization", "logo" : { "@type" : "ImageObject", "url" : "https://www.carboncollective.co/hubfs/CarbonCollectiveLogo.png" }, "name" : "Carbon Collective" } } ```