They're the next best thing to a crystal ball.

Each product we feature has been independently selected and reviewed by our editorial team. If you make a purchase using the links included, we may earn commission.

As a relationship columnist and dating self-help author, I get asked the same questions over and over again. One of the trickiest to answer is one of the most common: When should I know if I want to be with my partner for the long haul?

Whether it’s marriage or simply lifelong commitment, most people do want to find a relationship that goes the distance. And at one point or another, they start to wonder if their current partner could be The One, Mr. or Ms. Right, or that “forever” person.

I’ve seen all sorts of stories and all types of commitment trajectories. I want to emphasize this: There is no normal. Some claim to know immediately or within the first few months, others can take several years (or more) to determine if their partner is the right person. It all depends on different factors, including age when you met, life stage, milestones, feelings, shared history, and potential of the relationship.

While there is no normal, there are some averages. A 2016 survey of 2,000 revealed the average rate a couple hits major milestones. The typical couple had a conversation about the future within a year, got engaged after 743 days (a little over two years), and got married after 1190 days (just over three years). However, other sites and surveys have reported completely different figures.

Based on my field observations and research, I believe it’s less about when in terms of months or years, and more if you’re hitting key milestones with your partner—because if you’re not, you may never. If you’re struggling to know if your relationship can (or should) go the distance, here are some questions to ask yourself.

Are you still figuring out where (and who) you want to be?

It’s taking adults longer than ever to settle down, which is why psychologist Jeffrey Arnett coined the term “emerging adulthood." Arnett claimed emerging adulthood was the period from age 18 to 29 where young adults are getting acclimated to life on their own. This includes a focus on self; tons of transition, like moves and job changes; and exploring what they want out of education, career, and love.

If you’re roughly in this age range and experiencing these changes, you might not yet know if the person you’re with is the one for you. On a basic level, if you don’t know what your future looks like, then you cannot possibly know what people belong in your future. If you don’t know who you are and what you bring to a relationship, then you cannot possibly feel confident in yourself as a partner or who might complement you as a partner.

You might also feel yourself slide back into an emerging adulthood-like period following a divorce or other major life change, where you need to re-determine who you are and where you’re going. If you’re in the middle of personal discovery, give it time.

Have you really thought about what you want in a long-term partner?

After you’ve figured out who you are and where you’re headed, you need to figure out what you want in a partner. What will make for a good, compatible relationship? You may not be able to answer that question until you’ve dated around and done some evaluation in the aftermath: What worked? What didn’t?

Honestly, there is no substitute for gathering data here; it’s why I’ve seen some men and women get together very young, break up, and then get back together years later. It wasn’t that they were wrong for each other, but without gathering data, they would never have known if their first relationship was the right one.

If you are perfectly happy in your relationship, and you haven’t dated much but feel no desire to, then you may be okay relying on averages as checkpoints, so give yourself a couple years. If you’re racked with doubt about your partner, unsure whether they’re incompatible or simply a human with flaws and differences, you might need to date around and gather more relationship data.

Have you been making deliberate decisions together?

I read this study a while ago, and I always found it to be quite true in determining whether a commitment is going to pass the test of time: When hitting milestones with your partner, did you decide or did you slide? Research from the University of Virginia has noted married couples who “decide” to be together or move in together are typically happier in their commitments.

Here’s what that might look like, in practice, as I’ve seen it play out. Did you slowly move all your stuff to his place, or did you decide you wanted to live together? Did you begin as a hookup, and then never have a conversation about commitment or stop to think if you’re really compatible? Did you run into your friends on an early date or get-together, and then just gradually bring your significant other around more often, or did you think early on, ‘I really want my friends to meet Bill’? If the former on all fronts, hold off.

Your attitude toward milestones can be telling. Were you excited to take each step? Did your excitement stay the same or grow with time? If not, are you excited for a future now? If you’ve been consistently excited and deliberate about your relationship, you might just have cold feet about lifelong commitment. If you simply slid or felt apprehensive about steps (common in this casual culture), your commitment might look strong, but not feel strong—or be strong.

If you take away your shared history, would you still be interested in your partner?

Imagine that you’ve lost all history and familiarity with your partner. No shared memories, no past milestones, no synched-up lifestyles. However, you still know what this person is like as a partner, as well as who they are as a person and what they want long-term. Would you date them again? Or seeing them without history attached, would you choose to date others?

I say it all the time: History and familiarity with a partner can enhance your connection, but it is not the connection itself. Sometimes, you might love someone, but find yourself constantly butting up against incompatibility. You want kids; he doesn’t. You want to live in the suburbs; he wants to live in a city. You constantly want more sex than your partner. Your partner wants more attention than you have to give, ending in regular arguments.

Don’t fall victim to the “sunk costs” effect. In psychology or behavioral economics, this means you continue to make a poor decision instead of a rational choice, because you’ve already invested (time, money, energy) into it. In relationships, this is when you continue a relationship that isn’t really working because you’ve already invested in this person and built history. Deep down, you know the right choice is to break up. But love and dating is highly emotional! I know. Just remember: Sometimes you need to make rational choices to find the long-term love you truly want, hard though they may be.

Does your partner “expand” you?

Let’s say you’ve done all the work to know yourself and what you’re looking for, and you’re still a little unsure. Committing today is more complex than ever, after all; we want our significant other to be a partner and a lover, a best friend and a rock. Throughout researching my book, I was looking to find one solid way to determine if a relationship was really right.

Over time, I kept coming back to psychologist Art Aron’s self-expansion model of relationships. At their core, good relationships make us more. We are excited to spend time with someone, because they offer us new perspectives, they enhance our thinking, we can go on adventures together, and they generally help us grow.

To get our best wellness tips delivered to you inbox, sign up for the Healthy Living newsletter

Here’s the question I think you should ask when it comes to commitment: Does your partner expand you? Everyone’s idea of expansion will be a bit different; growth can be found a million different ways. However, recent research has found that partners felt best in relationships that helped them become closer to their “ideal self” and not their “actual self,” aka, relationships that helped them grow and become better.

Of course, there are seasons for every relationship—some more exciting than others. But overall, I hope you find a partner who expands you and betters you. If you’ve got that, hang onto it.

Jenna Birch is author of The Love Gap: A Radical Plan to Win in Life and Love (Grand Central Life & Style)