skip to Main Content

Erfun Geula

Erfun is a professional GMAT tutor based in Manhattan, with over 12 years and 12,000 hours of standardized test tutoring experience. He has been a full-time GMAT tutor for the past nine years, but his experiences since graduating from Yale have all, one way or another, revolved around standardized tests.

Before focusing his efforts on GMAT tutoring, he worked in New York full-time as GMAT Content Developer and Instructor for a major test-prep company, where he wrote, edited, and explained hundreds of practice GMAT questions. His immersion in the process of question-construction gave him first-hand insight into the tricks that the test-makers develop and the crafty ways they manipulate seemingly simple concepts into complex puzzles. Additionally, Erfun is sole author of McGraw Hill’s Preparation for the GRE, 2017 Edition, a 500-page, comprehensive guide available on Amazon and at all major book stores.

As a bona fide GMAT geek, Erfun is one of the few people in the world who can boast of having scored in the 99th-percentile (760+) on all four of his GMAT attempts, including a perfect Quantitative score of 51 and a Verbal score of 48 (99.5th percentile). He now uses his substantial expertise in the GMAT to help students see past superficial tricks and shortcuts and understand the logic of the exam. He has helped students gain admission to some of the nation’s top business schools, including HBS, Columbia, Stern, Wharton, Stanford, and Sloan. And he’s one of the most consistently well-rated GMAT tutors in the world, as evidenced by the numerous 5-star testimonials of his services.

GMAT Tutor in NYC & Online

  • Full-time New York GMAT tutor, with over 15 years and 15,000 hours of tutoring experience.
  • Scored in the 99th-percentile (760+) five different times on the GMAT Score Report
  • Wrote and edited hundreds of practice GMAT questions full-time for major test prep company
  • Yale graduate with Distinction
  • Published 600-page test prep book for McGraw Hill
  • Interviewed by US News for expert perspective on the GMAT & GRE
  • Hundreds of GMAT tutoring students successfully admitted to Harvard, Stanford, Columbia, NYU, Wharton, HBS, etc.
  • Excellent references: click here or here or here

The GMAT Compass Advantage


We work with a lot of New York GMAT clients who are busy professionals seeking to make the most out of their precious study time, so Erfun has used his years of experience to develop a proprietary system that includes homework assignments for every day of your preparation, a detailed error log tracking every mistake and providing real-time data on your strengths and weaknesses, and access to a suite of thousands of GMAT questions unavailable through other GMAT tutor or company.

Independent & Versatile

As an independent GMAT tutor, Erfun is unconstrained by the materials and methodologies of any one test-prep company. Instead of teaching you the gimmicks espoused by a certain test prep company, he adapts the curriculum and teaching style to your needs, with a core emphasis on developing and refining the fundamental reasoning skills that the GMAT measures.

Best Materials

Over the past 15 years, Erfun has pored through all of the materials available to develop a best-in-industry suite of thousands of practice questions structured by topic and level of difficulty. He uses only official GMAT questions and is able to customize the homework to ensure that it meets your specific needs. If you need brushing up on the basics, he has that covered. Or if you’re aiming for 730+ and don’t know where to find more materials, he has hundreds of difficult questions that will help you shore up your weaknesses.

Only 1:1 Tutoring

The big companies (Kaplan, Manhattan Prep, etc.) train their instructors to teach large classrooms of 20+ students. In contrast, Erfun works exclusively as a one-on-one GMAT tutor. He’s spent the past 15 years refining his methodologies and curriculum to ensure that every GMAT tutoring program is customized to the clients’ specific needs. Take a look at our case studies to see the level of depth Erfun goes into to ensure that the program is customized for you and your situation.

FAQs about GMAT Tutoring

This is an essential question to ask yourself before you spend thousands of dollars on a GMAT tutor. Generally, GMAT tutoring is most beneficial for students who:

  • Need to maximize the return on their study time. If you’re in a time-crunch with applications around the corner, or if you have a demanding job that limits your available study time, then hiring a GMAT tutor would probably be a good decision for you.
  • Benefit from structure and accountability. The amount of GMAT resources out there can be overwhelming. Hiring a good GMAT tutor will save you the headache of separating the good from the bad and will let you spend that precious time doing targeted, effective studying. A good GMAT tutor will structure your preparation to ensure that you have both an overall study plan governing your preparation and a structured homework plan for each week (and, ideally, each day!) of your preparation.
  • Are aiming for 730+. The dirty secret of most GMAT prep courses is that they target the median student. Because of this, the difficulty level of the classes and homework assignments rarely exceeds the 700-level. Working with a GMAT tutor who themselves have scored in the 99th-percentile and who have a documented track record of helping students achieve similar success is a high-probability way to position yourself to achieve a stellar score. 

Probably. About half of our clients come to us having already taken the exam, so we’re intimately familiar with the pitfalls that re-takers sometimes confront and the shortcomings of the courses and other study materials that they used in their prior preparation. Indeed, we pride ourselves on getting into the minds of our students and truly examining what has been holding them back. Over the years, we’ve worked with students who have taken the exam numerous times and felt that the GMAT was an impossible feat, but we’ve usually been able to identify concrete issues in their strategies— be it conceptual, time management, or reasoning-related— that helped make what they thought was impossible into a reality.

We’ve developed a best-in-industry suite of official materials that we’re able to tailor to the individual needs of all of our clients. If you hire us as your GMAT tutor, you’ll get:

  • Over 5,000 official GMAT questions customized by topic and level of difficulty
  • Access to over 70 GMAT videos made by our head tutor, Erfun Geula
  • A detailed, streamlined error log that will help you easily track and review your performance across your preparation
  • Day-by-day homework assignments pointing you to important official GMAT questions that reinforce what we cover at our lessons
  • “Refresher” PDFs covering all the major rules and formulas you need to know for the exam
  • For online sessions, we give GMAT tutoring students the ability to record our sessions for review later in the day

Yup. We meet most of our students online (even our New York City GMAT clients) and we’ve developed our system to work best for online tutoring. We have all necessary resources in PDF form, and we show our math on an online whiteboard that you can view in real-time through the Zoom platform. Better yet, online tutoring gives you the opportunity to screenshot questions we do together for later review and to record our meetings (this is something many companies don’t do, but we know how beneficial this is for our clients and are happy to do what we need to help them maximize their scores!).

GMAT Video Series

How to Calculate GMAT Scores

How to Calculate GMAT Scores GMAT scores are calculated by taking your scaled score from 6-51 on each section and…

How to Calculate GMAT Scores

How to Calculate GMAT Scores

GMAT scores are calculated by taking your scaled score from 6-51 on each section and arriving at a composite GMAT score from 200 – 800. Nonetheless, there’s a lot of confusion about how to calculate GMAT scores, so we’ll do a deep dive in this article to address that confusion.

What is a computer-adaptive test?

Put simply, a computer adaptive test adjusts the level of difficulty of each question you see based on your performance on previous questions. The harder the questions you’re answering correctly, the harder later questions will be, and the easier the questions you’re missing, the easier subsequent questions will.

The purpose of the GMAT CAT is to efficiently tailor the level of difficulty of questions to a test-taker’s specific abilities. This allows the exam to more efficiently assess your abilities than an exam with linear scoring would. To understand the difference between adaptive and linear scoring, let’s look at two examples:

Linear scoring is what most of us experienced in our high school and maybe college educations. On exams with this type of scoring, you’ll be presented with a fixed number of questions, and your overall score will be determined by the percentage of questions you get correct, independent of which questions you answered correctly or incorrectly. This type of scoring certainly provides useful data, but it lacks the level of granularity that computer-adaptive scoring provides.

Imagine the following scenario: Mary is a quant genius who effortlessly answered all 30 questions on a linearly-scored test with time to spare. Bob is strong at Quant and was able to answer all 30 questions correctly just in the nick of time. As far as linear scoring is concerned, these two performed identically. But here’s the thing: Mary would have been able to answer even tougher questions that Bob probably would have answered incorrectly. But the nature of this kind of exam doesn’t give Mary the opportunity to showcase those skills. An adaptive exam, by contrast, will recognize that Mary and Bob are acing the questions and will ramp up the level of difficulty of the questions presented to them. Since Mary is stronger at Quant than Bob is, she’ll eventually get certain questions correct that Bob would have missed, and her GMAT score will be higher than his as a result.

So, ultimately, computer-adaptivity serves to help the test-makers efficiently identify someone’s precise abilities on an exam at a level of granularity unavailable with linear scoring.
How are GMAT scores calculated?

Because the GMAT is computer-adaptive, GMAT scores are not determined by the number of questions answered correctly. Instead, GMAT scores are primarily determined by the level of difficulty of the questions you miss. Let’s say Bob takes the GMAT Quantitative section and misses 10 “easy” questions distributed evenly throughout the exam. Since he’s missing easy questions, the algorithm will never adjust the level of difficulty of his questions to “hard”, so there will be a ceiling on his score: he’d probably score in the 30s or even 20s.

Now let’s say Mary takes the Quant section and misses 10 questions, but all “hard”. In this case, the scoring algorithm will recognize that the questions she missed were at a high level and will consequently give her a higher score, possibly as high as 48 or 49.

The essential point is this: the algorithm wants to identify the level of difficulty at which you plateau. If you plateau at a level of difficulty of 30 (in other words, if this is the level at which you consistently miss questions), then your score will be a 30. 

GMAT Quant and Verbal Scaled Scores

GMAT Quantitative and Verbal scores range from 6 – 51, in 1-point increments. The GMAT website claims that scaled scores can go as high as 60, but there has never been a reported Quantitative or Verbal score higher than 51, even among people who answered every question on a section correctly. 

Calculating Your Composite GMAT Score

Unfortunately, GMAC has never released publicly available data about the relationship between scaled scores and composite GMAT scores. However, tables such as this one, and people’s anecdotal reports on websites such as GMATClub can give you a pretty good sense of which scaled scores translate to which composite scores. That said, there are a couple important points to keep in mind:

#1) A given scaled score can have a range: If you take the GMAT and get a scaled score of 47 on Quant, that score can actually be anything between 46.5 and 47.49. Because of this level of nuance, two people with the same scaled Quant and Verbal score can actually see a 10 or 20-point difference in their composite scores.

#2) Summing your composite score doesn’t give the whole picture. For reasons we’ll get into below, the GMAT scoring algorithm slightly weights Verbal scores more than Quant scores. So a 45 Quant, 40 Verbal will sometimes be 10 points lower than a 40 Quant, 45 Verbal.

GMAT Quant and Verbal Percentiles

This is where things get interesting. If you compare the percentile of a Quantitative 40 to a Verbal 40, you’ll notice something interesting: Despite being the same scaled score, the Verbal percentile is significantly higher!

Why is this the case? Over the years, Quantitative percentiles have been dropping, while Verbal percentiles have stayed about the same. The drop in Quantitative percentiles is largely attributable to an influx of international test-takers over the past decade: for various reasons, these test-takers tend to perform better on the Quant than do American test-takers, so higher quant scores have become more common, leading to a lower corresponding percentile for each scaled score. These same test-takers tend not to do as well on Verbal, so the corresponding percentiles for a given Verbal scaled score have largely plateaued.

What’s a good GMAT score?

“Good” is of course a relative term. Your desired score should depend on the median GMAT of the schools you’re applying to, along with the competitiveness of the rest of your application. Generally, schools use GMAT scores to 1) assess your readiness to handle their coursework and 2) drive their rankings on US News. These rankings contribute significantly to school reputations and school funding.

GMAT Algebraic Translations

Having trouble with GMAT word problems? In this video, we'll cover powerful techniques to successfully tackle GMAT questions. We'll provide…

GMAT Algebraic Translations

Lesson Overview

Having trouble with GMAT word problems? In this video, we’ll cover powerful techniques to successfully tackle GMAT questions. We’ll provide you with a step-by-step method for turning wordy questions into algebra, and we’ll cover common mistakes students make when tackling word problems. We’ll cover how to identify unknowns, how to assign variables, and, importantly, how to find words and phrases in the question that lend themselves to creating an algebraic equation.

Ace the GMAT

If you’re ready to move forward, or just want more information, the first step is to get in touch.

GMAT Standard Deviation

Having trouble with GMAT standard deviation questions? Though standard deviation isn't a huge topic on the GMAT, it's one that…

GMAT Standard Deviation

Lesson Overview

Having trouble with GMAT standard deviation questions? Though standard deviation isn’t a huge topic on the GMAT, it’s one that you need to master if you want to achieve a Quant score in the 45+ range. In this video, we cover everything you need to know to master standard deviation on the GMAT. We’ll examine how standard deviation differs from other statistical measurements, an informal way of measuring standard deviation, and situations in which the standard deviation of a set does and does not change.

Ace the GMAT

If you’re ready to move forward, or just want more information, the first step is to get in touch.

Schools Our Clients Attend

Back To Top