Joining Mensa comes down to one thing: proving you score in the top 2% on intelligence — meaning your reasoning ability, as measured by a recognised IQ test, outranks 98 out of 100 people. There are exactly two accepted routes to do that. You either sit Mensa's own supervised admission test, or you submit documentation from a qualifying test you've already taken elsewhere, such as a school or clinical assessment. That's it — no essays, no interviews, no "proving yourself" beyond the number.
If you landed here wanting the short version: pick a route, pay the fee, submit your proof, wait for verification. The rest of this guide walks through both paths properly, because the details — costs, age rules, which old scores actually count — trip a lot of people up.
What is Mensa, quickly
Mensa is an international society founded in the UK in 1946, built around a single admission rule: score at or above the 98th percentile (percentile meaning the percentage of people your score beats — the 98th percentile means you outscored 98% of the reference group) on an approved intelligence test. It doesn't test for anything else. No background checks, no minimum education, no application essay about why you'd be a good member. If you've covered the what is Mensa basics already, you can skip ahead — otherwise it's worth a quick read, since it explains why the society only cares about one number and how local chapters ("national Mensas") vary slightly in process.
The 98th percentile on most standard IQ scales (mean 100, standard deviation 15 — meaning scores spread out from the average of 100 in fixed increments, with about two-thirds of people falling between 85 and 115) works out to roughly IQ 130 or above. The exact cutoff depends on the specific test and its own scoring table, which is why Mensa doesn't publish one universal number. We've broken this down in detail in our piece on the Mensa IQ requirement, including why "130" is a useful shorthand but not a strict rule across every test format.
The two accepted routes in
Route 1: Take Mensa's own supervised test
This is the route most people use, and it's the simplest to plan around because you don't need to hunt down old paperwork.
Mensa administers its admission test under supervision — meaning a proctor watches you take it, in person or via monitored remote video, to confirm it's really you and that you're not getting help. This matters because an unsupervised online test, however well-designed, can't be used for Mensa admission. Supervision is what makes a score verifiable.
Typically the process looks like this:
- Register with your national Mensa (the US, UK, and most countries run their own testing programmes).
- Pay the testing fee, which usually falls somewhere between $40 and $60 USD (or the local equivalent) depending on country and format.
- Sit the test at a scheduled session — often a Wechsler-style or Cattell-style battery, proctored in a testing centre or online with camera supervision.
- Receive your score. If you clear the cutoff, you're offered membership. If you don't, most national Mensas allow a retest after a waiting period, commonly six months to a year.
One quirk worth knowing: Mensa's test isn't a single fixed exam. Different national branches use different approved instruments, and some offer two-part sessions (one verbal, one non-verbal) where hitting the cutoff on either part is enough to qualify.
Route 2: Submit a prior qualifying score
If you've already taken a recognised, individually-administered IQ test in the past — through a school psychologist, a clinical evaluation, or certain professional assessments — you may be able to submit that documentation instead of retesting.
The catch is in the word "qualifying." Not every test counts. Mensa maintains a list of accepted instruments, generally limited to well-established, professionally administered tests like the WAIS (Wechsler Adult Intelligence Scale), certain Stanford-Binet versions, or other individually proctored batteries. Group-administered school tests, most online tests, and anything without a supervised, standardised administration typically don't qualify — even if the report looks official. Our comparison of WAIS, Raven and other test types explains what separates these from the quick assessments you'll find online, and why the distinction matters here.
To use this route you'll usually need:
- Original score documentation from a licensed psychologist or the testing institution (not a photocopy of a summary page you wrote down).
- Proof the test was on Mensa's approved list at the time it was taken — this can vary by decade, since accepted tests get updated.
- The percentile or standard score clearly stated, since raw scores alone aren't enough for verification.
Some national Mensas cap how old the qualifying score can be — a few require it to have been taken as an adult, or within a certain number of years. It's worth checking with your specific national Mensa before assuming an old school test will work.
Mensa membership requirements at a glance
| Requirement | Supervised test route | Prior score route |
|---|---|---|
| Cutoff | Top 2% (roughly IQ 130+, test-dependent) | Same cutoff, on an approved test |
| Supervision | Proctored by Mensa or partner centre | Must have been supervised at original administration |
| Cost | ~$40–$60 testing fee (varies by country) | Often a smaller review/admin fee |
| Age | Most countries: adult test from a set age (commonly 14+ for full admission; some offer youth membership under set conditions) | Depends on the age at which the original test was taken |
| Retake rules | Usually one retest allowed after 6–12 months | Not applicable — you're submitting existing proof |
Costs and age rules genuinely vary by country, so treat the table as a general shape, not a universal price list.
Age notes people ask about
Mensa isn't only for adults. Most national Mensas allow younger applicants, though the process differs:
- Young children are sometimes admitted using school-administered IQ tests reviewed by Mensa's psychologists, since a full adult-style supervised test isn't appropriate at that age.
- Teenagers can often sit an adapted version of the standard admission test.
- There's typically no upper age limit — plenty of members join well into retirement.
If age-specific rules matter to you, check directly with your national Mensa's page, since this is one area where iqmetria can't give a single global answer.
Common misconceptions about joining
A few myths circulate enough that they're worth clearing up directly:
- "Any IQ test result gets you in." No — only supervised results from Mensa's own test, or documented scores from its approved list, count. A number from a casual online quiz, however fun, isn't admissible.
- "You need a perfect score." No — you need the 98th percentile, not the maximum possible score. Plenty of members are well above cutoff; plenty are just at it.
- "Membership proves general genius." Not quite — it verifies strong performance on a specific reasoning measure at a specific moment. It says nothing about creativity, emotional intelligence, or expertise in any field. For context on what IQ does and doesn't capture, see our explainer on what IQ actually measures.
- "You can use any home IQ test as proof." This is the one that catches people out most. Even accurate, well-built online tests are unsupervised by design, which automatically excludes them from both Mensa routes.
Where a free online test fits in
To be direct about it: iqmetria is an independent platform and has no affiliation with Mensa. Our free IQ test is orientative — a self-knowledge tool, not a certified or clinical instrument, and it cannot be submitted to join Mensa through either route above.
What it can do is give you an honest, ballpark sense of where you sit. If your result comes back well below the top 2% territory, that's useful information before you spend $40–$60 on a supervised test. If it comes back near or above that range, it's a reasonable signal that a real attempt might be worth pursuing — though only Mensa's own supervised test or an approved prior score can actually confirm it.
Key takeaways
- There are exactly two ways in: Mensa's own supervised test, or a documented score from an approved prior test.
- The cutoff is the top 2%, roughly IQ 130+ depending on the specific test's scoring table.
- Supervision is non-negotiable — unsupervised online tests don't qualify under either route.
- Costs typically run $40–$60 for the admission test; age rules and retest policies vary by country.
- A free online IQ test can hint at whether you're in range, but it isn't valid proof for admission.
None of this replaces checking your own national Mensa's current rules directly, since fees, accepted tests, and age policies do get updated. And as with any IQ result you get anywhere, including on iqmetria — treat it as a data point for self-knowledge, not a verdict on your worth or potential.
FAQ
What IQ do you need to join Mensa?+
You need to score at or above the 98th percentile on an approved test, which works out to roughly IQ 130 or higher on most standard scales — though the exact cutoff depends on the specific test's own scoring table, since not every test uses the same scale.
How much does it cost to join Mensa?+
The supervised admission test typically costs around $40–$60 USD (or local equivalent), plus an annual membership fee once you're accepted. Submitting a prior qualifying score usually involves a smaller administrative review fee instead.
Can you join Mensa with an online IQ test result?+
No. Mensa requires supervised testing — either its own proctored admission test or a documented score from an approved, individually-administered test like the WAIS. Unsupervised online tests, however accurate, aren't accepted under either route.
What happens if you fail the Mensa test?+
Most national Mensas allow a retest after a waiting period, commonly six months to a year. A single missed attempt doesn't bar you from trying again.
Is there an age limit to join Mensa?+
There's generally no upper age limit, and most countries offer routes for younger applicants too, including school-administered tests reviewed by Mensa's psychologists for children and adapted tests for teenagers. Exact rules vary by national Mensa.