What Is McKinsey Solve? A Guide to Redrock, Sea Wolf and SFL

McKinsey Solve is the gamified online assessment McKinsey sends to most consulting applicants before any interview. Today it contains two or three timed games: the Redrock Study (a data-and-math research case), Sea Wolf (a microbe-selection puzzle) and, on longer invitations, the Sustainable Futures Lab (a judgment module). No business knowledge is required, and every candidate gets different numbers.

This guide covers which games you will get, how long your invitation will be, how scoring reportedly works, what you may use during the test, and a three-week plan for getting familiar with the formats. Each game and each common question has its own detailed article, linked from the table below.

A note on certainty. McKinsey publishes very little about Solve beyond its official FAQ. Everything else in this guide (game timings, question counts, scoring mechanics) comes from candidate reports compiled by prep providers. We label those claims as reported, and the page shows the date each fact was last checked.

minutes on the two most common invitations (reported)

65 / 85

Source: myconsultingcoach.com

minutes for Redrock, the game on every current invitation (reported)

35

Source: strategycase.com

estimated share of test takers who pass (third-party estimate)

20–30%

Source: careerservices.fas.harvard.edu

languages McKinsey offers Solve in

4

Source: mckinsey.com

Where to go next: every Solve question, answered in depth

What is McKinsey Solve?

Solve is a gamified online assessment. It puts you in a simulated natural environment (an island ecosystem, an ocean with contaminated sites, a research study on a species) and asks you to make decisions with data. McKinsey's careers page calls it "a gamified assessment that tests your natural problem-solving abilities" and says it is "one of the exciting steps in our process for most consulting roles" (McKinsey).

Three things make Solve different from a classic aptitude test:

• No business knowledge is needed. McKinsey's FAQ says Solve "does not require previous business knowledge or gaming experience." The scenarios are about biology and ecology, not revenue and cost, so a finance background gives you no head start.
• Every candidate gets different numbers. McKinsey states that Solve "uses advanced AI methods to ensure that there is ample variation in each scenario" and "is designed so that no two individuals have the same parameters and combinations of data" (McKinsey FAQ). Memorized answers are useless, so the only thing worth practicing is method.
• It is one input, not the decision. McKinsey says results are "taken into consideration together with the rest of your application and any other assessment results." A strong Solve does not guarantee an interview, and a borderline one does not automatically end your application.

PSG, Imbellus, Digital Assessment, Solve: one test, several names

You will see the test under four names, and they refer to the same thing at different points in its history.

Solve replaced the paper-style McKinsey Problem Solving Test (PST), which Tufts describes as "a more traditional GMAT-style test" (Tufts Career Center). The PST skills still matter, though. Reading exhibits and doing fast percentage math are exactly what Redrock asks for.

Which games are in Solve now?

The game lineup has changed several times since the Imbellus era. Here is the status as of the "last verified" date on this page.

Sources: MyConsultingCoach, psgsecrets, StrategyCase, CaseBasix.

Sea Wolf's timing is the one real disagreement among sources. StrategyCase, MConsultingPrep and psgsecrets say 30 minutes, and CaseBasix says 35. The 30-minute figure matches the 65-minute invitation (35 + 30), so we use it here, but your on-screen timer is what counts.

65 vs 85 minutes: what your invitation length tells you

McKinsey's current FAQ says only that "the length of your Solve assessment is outlined in your invitation email." It does not say which games each length contains. Candidates and prep providers, however, report a consistent pattern.

Two practical consequences follow:

1. Pace each game against its own limit. Prep sources describe a separate time limit per game (35 for Redrock, about 30 for Sea Wolf, 20 for SFL). Do not count on time saved in one game being available in the next.
2. Budget more time than the invitation says. Each task "will begin with an untimed tutorial" (McKinsey FAQ). StrategyCase estimates 5 to 10 minutes of tutorial per game, so book a two-hour quiet slot for an 85-minute invitation.

The Sustainable Futures Lab guide covers the 65 vs 85 question in more depth, including how to read the invitation email.

How is McKinsey Solve scored?

McKinsey has not published a scoring model. What is widely reported by prep providers is a split between two signals:

• Product score: how good your final outcome is. Are the Redrock answers correct? Do your chosen microbes meet each site's constraints?
• Process score: how you got there. Which data you collected, in what order, how much you backtracked, and how you used the clock. CaseBasix's summary is that "every click, drag, and decision you make is tracked."

A few points are firmer than the rest:

The practical lesson from the process signal: decide what you need before you click. Read the objective, work out which numbers the later steps will need, and collect those. Collecting everything "just in case" and dragging items back out is the pattern most guides warn against.

For deciles, office differences and what a "good" score looks like, read McKinsey Solve score and pass rate.

What is the Redrock Study?

Redrock is a short, timed research case. You play a researcher analyzing fictional wildlife data (Road to Offer mentions wolf packs and elk across regions) and move through a fixed sequence of phases. Candidates describe two parts inside the 35 minutes.

Part 1: the study.

1. Investigation. You read text, charts and tables and drag the relevant data points into a research journal.
2. Analysis. You answer calculation questions using the data you collected. Road to Offer notes that some versions include an on-screen calculator.
3. Report. You complete a partly written report: fill in numbers, choose "higher" or "lower", and pick the chart type that best shows a finding.

Part 2: the cases. A set of standalone mini-cases on related themes, six in current versions according to Road to Offer and psgsecrets (psgsecrets says the count fell from ten). Each one is self-contained, so a mistake in one does not spoil the next.

The flow runs one way. Road to Offer notes that "once you advance you cannot return", so a data point you skipped in Investigation stays skipped. Its other practical tip: if your version has a calculator log, chain unrounded results from it, because rounding errors cascade through later answers.

How to split Redrock's 35 minutes

No official split exists. Two prep providers publish suggested splits, and they agree on the main point: protect at least 10 minutes for the cases.

A worked example of Redrock-style math

The math is simple, but it is easy to get wrong under time pressure. Here are two traps built into a Redrock-style question. The numbers are invented for illustration and are not from the real game.

Trap 1: percent vs percentage points. A species' diet was 20% fish last year and 26% fish this year. The increase is 6 percentage points, which is a 30% relative increase (6 ÷ 20). The answer choices will usually include both. Read which one the question asks for.

Trap 2: simple vs weighted average. Three zones hold 400, 250 and 350 animals with average weights of 12 kg, 18 kg and 10 kg. The simple average of the three weights is 13.3 kg, which is wrong. The weighted average is (400×12 + 250×18 + 350×10) ÷ 1,000 = (4,800 + 4,500 + 3,500) ÷ 1,000 = 12.8 kg.

For the report phase, Road to Offer's chart rules are a useful default. Use a bar chart to compare categories at one point in time, a line chart for a trend over time, a stacked bar for composition over time, a scatter plot for correlation, and a pie chart only for parts of a single whole.

How does the Sea Wolf game work?

In Sea Wolf (also called the Ocean Cleanup game) you treat contaminated ocean sites with microbes. Candidates report three sites. At each one you build a prospect pool of about ten microbes and choose three to treat the site (MConsultingPrep, CaseBasix). Each microbe has numerical attributes and traits. Each site has a target range for each attribute and conditions on traits it wants or must avoid.

The key rule, as CaseBasix and Road to Offer describe it, is that the average of each attribute across your three microbes must fall inside the site's range. No single microbe has to be in range on its own.

The averaging rule in one line

Turn the range into a band for the sum. If a site wants attribute A between 5 and 7, the three microbes' A values must add up to between 15 and 21 (three times each end of the range). Adding three whole numbers and checking them against a band is faster than averaging each time.

Illustrative example (invented numbers): candidates have A values of 8, 4, 6 and 9.

Microbe 4 is out of range on its own, but it is useful because it pulls a high microbe back into the band. This is the step candidates most often miss.

Sources describe the trait conditions slightly differently, so check the site brief in the game each time. CaseBasix's reading: at least one microbe must have the desired trait, and none may have the undesired trait. The Sea Wolf averaging rule article walks through elimination order, time per site and three full practice scenarios.

What is the Sustainable Futures Lab?

The Sustainable Futures Lab (SFL) is the newest module. It appears only on longer invitations. psgsecrets dates its arrival to March 2026, and MConsultingPrep to early 2026. Unlike Redrock and Sea Wolf, SFL is closer to a situational-judgment test: you run a sustainability project and make calls about priorities, trade-offs and your team.

The reported format in its 20-minute version:

How SFL answers are scored is not public, and it may not be a simple right-or-wrong key. Be wary of any guide that claims to know "the correct answer" to judgment items. What you can practice is reading the scenario for the stated goal and constraints before you look at the options, and keeping your choices consistent from one question to the next. The Sustainable Futures Lab guide has a trait-by-behavior table and example scenarios.

How hard is McKinsey Solve, skill by skill?

"How hard is Solve?" has no single answer, because each game stresses a different skill. Here is where the difficulty comes from, based on the formats described above.

If you are strong at math but slow to read exhibits, Redrock is your risk. If you rush, Sea Wolf's constraints catch you. If you like a single right answer, SFL will feel uncomfortable. Put most of your practice time on your weakest column.

Can you use a calculator, Excel or notes on Solve?

McKinsey's current FAQ is explicit about what is banned. Unless a disability accommodation has been approved in writing, you may not:

• "Use applications, websites, AI tools, or pre-prepared notes"
• "Record or capture screenshots of any part of the assessment"

It also expects you to "participate in this assessment alone, without assistance from others." McKinsey's careers page adds a table in which "Using AI during assessments (unless specifically permitted)" is marked Not Allowed, while "Asking AI to explain concepts or frameworks as part of your prep" is Encouraged (McKinsey). Using AI to learn before the test is fine. Using it during the test is not.

What the FAQ does not mention is a handheld calculator or scratch paper. Prep sites disagree, sometimes with themselves: CaseBasix's system-requirements page says you cannot use Excel, while its full guide suggests keeping pen, paper and a calculator ready for Sea Wolf. MyConsultingCoach says not to assume any external tool is allowed unless the on-screen rules say so. The safe rule is to use the in-game calculator where one is provided and paper only if the on-screen instructions allow it. The calculator and tool rules article sets out every case.

Setup checklist

What happens on test day, step by step?

McKinsey's FAQ describes the sequence, and prep guides fill in the gaps. In order:

1. Open your link and pass the tech check. It runs before Solve starts and tells you whether your device meets the minimum specification. PC or Mac only.
2. Choose a language. English, Spanish or Portuguese (each in an Iberian or Latin American version), or Japanese.
3. Work through each game's untimed tutorial. McKinsey says it "directs you to the task's objective and provides guidance on how to navigate the task." Read the objective slowly here. The tutorial costs you nothing, and the timed task does.
4. Play the timed game. The clock starts after the tutorial. Repeat steps 3 and 4 for each game on your invitation.
5. If something breaks, contact support at once. Email gbil-support@mckinsey.com or use the live chat while the problem is happening. McKinsey says support can "offer you extra time or reset your link depending on the issue", but not if you report it afterwards.

The FAQ says nothing about showing you a score when you finish. Your recruiter makes the decision, weighing Solve alongside the rest of your application and any other assessment results.

How should you prepare for McKinsey Solve? A 3-week plan

McKinsey's FAQ says "no preparation is needed", and its careers page says "there's no need to prepare." Each task opens with a tutorial. That is true in the sense that no outside knowledge is required. The case for preparing is time. Every minute of the timed clock you spend working out the interface or re-reading a rule is a minute you are not solving. Familiarization moves that learning to before test day.

This plan assumes about 45 to 60 minutes a day and an invitation that arrives with a few days' notice. Candidates report deadlines of roughly 3 to 7 days after the invitation (MConsultingPrep), so start before you apply if you can.

The night before, run McKinsey's tech check, charge the laptop, close other apps and book the two-hour slot. Then stop practicing.

DrillCase's McKinsey practice has 20+ Solve-style scenarios covering Redrock, Sea Wolf, the Sustainable Futures Lab and the legacy Ecosystem game, with one free demo scenario. They are original practice material, not copies of McKinsey's games, and they are built for rehearsal before the test.

When do you get Solve results, and can you retake it?

When you hear back. McKinsey does not publish a timeline. Third-party guides report "within one to two weeks" (Leland, via Harvard FAS), "7 to 14 days" (CaseBasix) and "1 to 14 days, depending on office processes and candidate volume" (StrategyCase). If you pass, the next step is interviews: for most client-facing roles, McKinsey says that means a Personal Experience Interview followed by a problem-solving (case) interview (McKinsey). The consulting assessment timeline compares this with BCG and Bain.

If you do not advance. Prep guides agree you cannot retake Solve in the same application cycle. The waiting period before you can reapply varies, and sources disagree:

The only reliable answer is your recruiter's. The failed Solve guide covers how to work out which game cost you and a 30-day re-prep plan.

What has changed in McKinsey Solve? A dated changelog

Solve changes more often than most guides are updated. This log records each reported change, its date and its source. We re-check it on the "last verified" date at the top of this page.

If your invitation or your games differ from this table, that is useful information. Let us know through the correction contact on our editorial policy page and we will check it and update the log.

The short version

• Read your invitation length first. 65 minutes means Redrock and Sea Wolf; 85 adds the Sustainable Futures Lab.
• Redrock rewards collecting only what you need and leaving time for the cases.
• Sea Wolf is an averaging problem. Convert each range into a sum band.
• SFL is judgment, not arithmetic. Read for the goal and constraints before the options.
• Practice before the test and use only the game's own tools during it.

For how Solve fits alongside BCG's Casey and Bain's online tests, see the MBB online assessments guide, or see how the DrillCase McKinsey Solve simulation works.