Welcome to GMAT Ninja!

Looking for an experienced private GMAT tutor in Denver or online? You’ve come to the right place.

We’re a trio of passionate, full-time, dedicated GMAT and GRE tutors, offering our services in Denver, Colorado – and anywhere there’s a good internet connection.

  • Charles Bibilos, GMAT Ninja founder, is one of the world’s most accomplished GMAT tutors, with more than 15 years of test-prep tutoring experience. Charles holds an M.A. in Education, and he graduated with distinction with a B.A. in Economics from Stanford University. He has earned perfect scores on the GMAT, GRE, and ACT, and he is also an accomplished writer of education curriculum.  Bio
  • Michael Maietta, the proud owner of a 99th percentile GMAT score and a summa cum laude degree in Mechanical Engineering, developed his interest in tutoring more than a decade ago, and joined GMAT Ninja full-time in 2016, after several successful years as a management consultant and private tutor.  Bio
  • Dave Goldstein has taught test prep since 2004, winning teacher-of-the-year awards from two large test-prep companies before joining GMAT Ninja. Dave is the ultimate academic Swiss army knife: he graduated magna cum laude with a concentration in Finance from the Wharton School and earned an MFA in Creative Writing from Emerson College.  Bio

For more on our tutoring or MBA admissions services — or to learn more about the GMAT and GRE in general — please visit the following pages:

And if you want to read unsolicited, online testimonials about our GMAT and GRE tutoring services, click here or here or here or here or here or here or here or here or here or here or  here. Charles was even interviewed for a GMAT article in U.S. News & World Report, and we were recently appointed as GMAT Club’s resident GMAT verbal experts.

If you’re ready to get started, click here to learn more about GMAT tutoring, or click here to contact us.

Thank you for visiting, and best of luck with your GMAT, GRE, and MBA goals!