FindZOPA

The ZOPA is the range of prices that both parties in a negotiation are willing to accept. For example, if a car seller wants at least $5,000 for his vehicle, and a buyer would be willing to pay up to $7,000 for the vehicle, then the ZOPA is the range from $5,000 to $7,000, since any of these prices would satisfy both parties. Of course, some negotiations have no ZOPA; this occurs where the seller's minimum acceptable price is above the buyer's maximum acceptable price.

FindZOPA is simple to use! Just create a session, select your role (buyer/seller), and enter your reservation (best) price. Then share your unique session ID with your counterparty, so they can enter a price as well. Be sure not to close your window, since you can't recover the session after closing the window.

If someone sent you a session ID, enter it to join the session. Then choose your role and enter a price.

After both parties have submitted prices, they will see a message indicating whether there is a ZOPA or not. If there is a ZOPA, they will be offered the chance to see FindZOPA's suggested price. This is only revealed if both parties agree, and is completely optional.

Simply put, we help you figure out whether you're wasting your time in a dead-end negotiation, or if a win-win agreement is waiting to be found.

In a negotation, parties understandably don't want to be first to name a price. The first party to name a price risks offering an overly-ambitious price (which could turn off the other party), and also risks offering an overly-generous price (which could leave too much money on the table).

FindZOPA solves this problem by acting as a trusted third-party that accepts prices from both parties simultaneously and confidentially. And because the parties know that the prices they give will not be revealed, they are incentivized to give their true reservation price. If there is room for a win-win agreement, FindZOPA lets them know that continued conversation should be fruitful—and if not, it saves them from investing more time in a dead-end negotiation.

If a ZOPA exists, we offer chance to receive a suggested price, which we have calculated based on the parties' ZOPA range. We only reveal the suggested price if both parties agree to do so, since this price—though it is selected via a randomizing algorithm—does implicitly reveal some information about the other party's submission.

Our suggested price (which is only revealed if a ZOPA exists, and if both parties agree to reveal the suggested price) is calculated as follows: First, we identify the middle 30% of the ZOPA, then we randomly select a price from within this range.

We calculate the suggested price in this way in order to ensure that not too much information about the parties' reservation prices is revealed. That is, if we returned the exact midpoint of the ZOPA, then each party could easily calculate the other party's reservation price. The prospect of this could lead parties to be less truthful in sharing their actual reservation prices.

Our method never reveals the precise reservation prices, since the parties don't know if the suggested price is closer to the top or bottom of the 30% range from which it is selected. This uncertainty keeps intact the incentive for both parties to be completely honest when submitting their reservation price.

Note that if both parties submit the same exact price, the suggested price will always be that price (which means that in this unique scenario, both parties' submissions will implicitly be revealed. However, this is perhaps not a bad thing, since it only happens when both parties are in agreement on the right price!

If you've never heard of a ZOPA before, fear not! We've compiled a list of several key definitions to help you use this site, and understand your negotiation better.

ZOPA: The Zone Of Possible Agreement, or the prices that would satisfy both parties. Not all negotiations have a ZOPA; for example, when the buyer's maximum price is below the seller's minimum price.

Reservation price: A party's reservation price is the most accommodating price that he will accept. For a seller, the reservation price is the minimum price at which he would do a deal; for the buyer, it is the maximum price he is willing to pay.

The term reservation price tends to be used more in the context of sellers (and particularly in auctions), but it technically also refers to a buyer's maximum price.

BATNA: A party's Best Alternative To a Negotiated Agreement is referred to as the BATNA. If you're selling your car on Craigslist and know that a dealer would give you $4,000 for it, then $4,000 is your BATNA when considering Craigslist offers.

When deciding on your reservation price, keep in mind what your BATNA is. What would you do if this deal fell through?

To learn more about negotiating, check out seminal books like Getting To Yes, Never Split The Difference, or Possible (the book that inspired this website).

We don't use your data except to determine if a ZOPA exists and to (optionally) calculate a suggested price. The price you enter is not stored after your session is completed, and it is never linked to your email (which we never ask for), your search history, your social media profile, your inseam length, or your shoe size.

FindZOPA is a free service that we built for our own internal use, and which we decided to make available freely so anyone can use it. So long as it doesn't consume substantial resources to run (which we can't imagine), it will remain free indefinitely.

If you like FindZOPA, please email us to tell us the story about how you used it in your negotiation, tell your colleagues about FindZOPA, and check out the other tools we've built (to help people read faster on screen and to help people balance their news diets).