Case Interview Guide: How to Crack Consulting Rounds
A stage-by-stage plan for practising cases, structuring out loud, handling the maths under pressure, and following up after each consulting round.
By Olu Adeyemi · Sep 29, 2026 · 12 min read
By the end of this guide you will know how to build a practice schedule you can actually keep, how to open, structure and close a case out loud, what interviewers watch for while you talk, and what to send after each round.
It covers candidate-led and interviewer-led cases, market sizing, exhibits, written cases and the fit questions that sit alongside them. The specifics vary by firm, office and round, so treat every timing here as a default you adjust once you know the format.
Before
Six to eight weeks out
- Read one case-method book end to end in the first ten days at about 20 pages a night, then stop reading and start doing. Reading past that point replaces practice rather than supporting it.
- Drill mental maths three times a week for 10 minutes: percentages, two-digit by three-digit multiplication, fractions converted to percentages, breakeven volumes, growth over several years. Do it on paper with no calculator, because most live rounds allow neither.
- Record a four-minute market sizing on your phone once a week and listen back once. You are checking for filler words, silence longer than five seconds, and whether you stated your assumptions before using them.
- Write a one-page inventory of the quantitative and client-facing work you have done, with the scope of each item: team size, budget, timeline, and the number that moved.
Four weeks out
- Do two live cases a week with a partner, 40 minutes each, split into roughly 30 minutes of case and 10 minutes of feedback. Book them as calendar invitations, not as intentions.
- Give as many cases as you receive. Spend 30 minutes preparing a case before you deliver it; sitting on the interviewer's side is the fastest way to see what weak structure sounds like.
- Build a bank of ten fit stories, each 90 seconds spoken and timed. Each one needs your role, the setting, the scope and what changed as a result.
- Practise exhibits on a 90-second timer: 20 seconds silent reading, then title, axes and units out loud, then one insight and one implication.
Two weeks out
- Increase to four cases a week and make at least two of them with people you have never met, so you practise structuring in front of a stranger.
- Run one written case: 20 minutes to read a pack of 15 to 20 slides, 20 minutes to build three slides, five minutes to present, five minutes of questions.
- Do at least one practice case at the same time of day as your interview, in the same room, in the clothes you plan to wear.
- Prepare three questions per interviewer about their practice area or recent work, written down.
Final 48 hours
- Stop taking new cases 24 hours before the round. Do one 15-minute maths drill on the morning of, nothing more.
- Confirm logistics 48 hours ahead by email if anything is unclear: round format, number of interviewers, length, whether a calculator is permitted, and whether there is a written component.
- Test the setup 12 hours ahead for a video round: camera at eye level, a lamp facing you rather than behind you, headset tested, phone on silent and face down, notifications off.
- Lay out your kit the night before: two working pens, ten sheets of blank paper turned landscape, a glass of water, and a printed copy of your CV within reach.
During
- Play back the prompt in two sentences and state the objective as a number and a deadline — for example, whether the client wants margin restored to a stated level within two years.
- Ask two or three clarifying questions at the start, one at a time, and say why you are asking each one.
- Ask for structuring time, name the length — "may I take 60 seconds" — and come back inside it.
- Signpost before you talk: say how many branches you have, then walk them in order without adding new ones mid-sentence.
- Tie your structure to this client, not to a template. Name the actual revenue lines, cost lines or customer segments in question.
- State a hypothesis early and say out loud when the data changes it.
- Before any calculation, say the formula and the units, then compute. Round openly and say that you are rounding.
- Sanity-check every answer against something real: a per-store figure, a per-customer figure, a share of the market you already sized.
- On an exhibit, take 20 to 30 seconds of silence, then read the title, axes and units aloud before you interpret anything.
- Follow each number with its implication. If you cannot say what the number means for the client's decision, say so and move on.
- Check the clock at the halfway point and say where you are: which branch you have closed, which one you want next.
- Ask for data by naming the decision it would change, rather than requesting everything available.
- Keep a separate sheet headed "answer" and add one line to it after each branch, so your synthesis is written before you are asked for it.
- When you are stuck, say what you would want to know and why, rather than going quiet.
- Deliver the close in under 90 seconds: recommendation first, two or three supports, one risk, one next step.
Closing synthesis, final round, profitability case
My recommendation is that the client, a 40-store regional bakery chain, exits the eight lowest-volume stores over the next 12 months and holds prices flat. Three things support that. First, gross margin is stable across the estate, so the problem is fixed cost, not pricing. Second, those eight stores each sit below the volume needed to cover rent and staffing, and the gap is wide rather than marginal. Third, closure costs are one-off, while the losses recur every year. The main risk is losing wholesale accounts that are served from two of those sites, so I would check delivery routing before confirming the list. As a next step, I would ask for lease break dates and 12 months of store-level volume to sequence the closures.
After
- Log the case within two hours, while you still remember it: prompt, your structure, the maths, where you hesitated, the feedback and one fix to practise this week. One page per case.
- Send a thank-you email within 24 hours — one per interviewer if you have their addresses, otherwise a single note to the recruiter asking them to pass it on. Keep it to about 120 words.
- Reference one specific thing from the conversation, not the firm's values. The case topic or something the interviewer said about their own work is enough.
- If you promised to send anything — a clarification, an article, a reference — attach it to that same email rather than sending a second message.
- Do not email a corrected calculation unless you were asked for one. It reopens the weakest moment of the round.
- Ask the recruiter for the decision timeline if nobody gave you one, in the same message.
- If the stated date passes, follow up once, three business days later, in three sentences.
- If you are offered feedback, take it, and come with two specific questions ready: one on structure, one on quantitative work.
- If you are rejected, thank them briefly and ask in the same reply how long the reapplication window is and whether they would look at you for another office or practice.
- Thank your practice partners and return a case to each of them within a week. Your practice network matters more in the second application round than in the first.
Thank-you email, sent the evening of a first round
Subject: Thank you — first-round interview, 14 March
Dear [name],
Thank you for the time this morning. I enjoyed the case on the bakery chain, and I have been thinking since about how lease break dates would change the sequencing — it was a useful reminder that the constraint is often contractual rather than financial.
I remain very interested in the role and in the operations work you described. If it is helpful, I am happy to provide anything further for the process.
With thanks, [your name]
What to avoid
| Mistake | Why it backfires | Fix |
|---|---|---|
| Reciting a memorised framework and forcing the case into it | Interviewers hear the same four templates all week and read it as pattern-matching rather than thinking; the branches stop mapping onto the client's actual problem within two minutes | Build the structure from the objective you just restated, and name the client's real revenue, cost or segment lines in each branch |
| Doing arithmetic silently, then announcing a number | If the number is wrong, nobody saw the method that was right, and a single slip costs you the whole branch | Say the formula and the units out loud, then compute, then sanity-check the magnitude before you interpret |
| Requesting data with no stated purpose | It reads as fishing, and it burns clock the interviewer has budgeted for the quantitative and closing sections | Pair each request with the decision it would change: "if churn is above X, I would drop this branch" |
| Producing numbers without saying what they mean | Analysis without implication is the most common reason a technically correct case is scored down; the competency being tested is judgement, not arithmetic | After every calculation, add one sentence beginning "so for the client, that means…" |
| Hedging the recommendation, or listing options instead of choosing | Consulting work ends in a decision a client can act on, so a balanced non-answer signals you would need supervision in front of the client | Lead with a single recommendation, then supports, then one named risk and how you would test it |
| Treating the fit interview as the easy half | Under-rehearsed stories run long, drift into team achievements, and leave no evidence of your own scope | Rehearse ten stories to 90 seconds each, with your role, the numbers you owned and the outcome |
Checklist
Six to eight weeks out
- [ ] One case-method book read once, then closed
- [ ] Mental maths drill scheduled three times a week, 10 minutes, no calculator
- [ ] One recorded market sizing per week, listened back once
- [ ] One-page inventory of quantitative and client-facing work, with scope figures
Four weeks out
- [ ] Two live cases a week booked in the calendar, 40 minutes each
- [ ] Giving as many cases as you receive
- [ ] Ten fit stories drafted and timed to 90 seconds
- [ ] Exhibit drill on a 90-second timer
Two weeks out
- [ ] Four cases a week, at least two with strangers
- [ ] One written case run end to end, including the five-minute presentation
- [ ] One case rehearsed at the interview's time of day, in the room you will use
- [ ] Three questions written per interviewer
Final 48 hours
- [ ] Format, length, calculator policy and written component confirmed with the recruiter
- [ ] Video setup tested: camera at eye level, light facing you, headset working, phone silenced
- [ ] Kit laid out: two pens, ten sheets of blank paper, water, printed CV
- [ ] No new cases in the last 24 hours
In the room
- [ ] Prompt played back; objective stated as a number and a deadline
- [ ] Clarifying questions asked one at a time, with reasons
- [ ] Structuring time requested, named and kept to
- [ ] Structure signposted and tied to this client
- [ ] Maths narrated: formula, units, rounding, sanity check
- [ ] Exhibits read aloud — title, axes, units — before interpreting
- [ ] "So what" stated after every number
- [ ] Halfway time check said out loud
- [ ] Running answer sheet maintained
- [ ] Close delivered in under 90 seconds: recommendation, supports, risk, next step
- [ ] Questions asked at the end
Afterwards
- [ ] Case logged within two hours, with one fix to practise
- [ ] Thank-you email sent within 24 hours, around 120 words, one specific reference
- [ ] Anything promised in the interview attached to that same email
- [ ] Decision timeline confirmed; one follow-up only, three business days after the stated date
- [ ] Feedback requested with two prepared questions, or reapplication window asked about
- [ ] Practice partners thanked and a case returned within a week
Frequently asked questions
How many practice cases should I do before a first round?
There is no fixed number, and counting cases tends to replace improving at them. Use fluency as the test instead: you are ready when you can take a case from a stranger, structure it inside 60 to 90 seconds, do the arithmetic out loud without losing the thread, and close with a recommendation in under 90 seconds — three times in a row, with different case types. Keep a one-page log per case and stop when the same weakness has not appeared for four consecutive sessions.
What should I do if I make a maths error mid-case?
Say it plainly, correct it and move on: "I have the units wrong — that should be per store, not total. Give me 20 seconds." Interviewers expect slips under time pressure, and how you recover is itself part of what is being assessed. What loses marks is defending a number you no longer believe, or going silent while you quietly redo the sum. Sanity-checking the magnitude before you interpret a figure catches most errors before they matter.
Do I need an MBA to get into consulting?
Not necessarily. A bachelor's degree is the typical entry-level requirement for management analysts, though some employers prefer candidates with an MBA (BLS, 2025), and suitable degree fields include business, social science and engineering (BLS, 2025). Requirements differ by firm, office and country, and many firms run separate entry routes for undergraduates, experienced hires and advanced-degree candidates. Check the specific route on the firm's careers page before assuming an MBA is required.
What should I expect on pay and hours if I get the offer?
Consulting pay is usually a base salary plus a performance bonus, sometimes with a signing payment, and it varies widely by firm, office, level and country. For context on the wider occupation, the median annual wage for management analysts was $101,860 in May 2025 (BLS, May 2025) and employment is projected to grow much faster than average from 2025 to 2035 (BLS, 2025) — but check current advertised ranges for your own market and level rather than relying on a national median. On hours, expect frequent travel to client sites and weeks longer than 40 hours (BLS, 2025); ask about travel expectations and staffing model in your own end-of-interview questions.
Sources
- U.S. Bureau of Labor Statistics — Management Analysts : Occupational Outlook Handbook (2025)
