NBME Score Conversion: CBSSA to Step 1 Converter (2024)

Looking for a Step 1 NBME score converter? Do you want to know what you would have scored on Step 1 before it went pass-fail? Are you confused about what to make of the new pass-fail Step 1 and NBME score reports?

If so, you’ve come to the right place. Here, we have created a CBSSA to predicted Step 1 score converter. HINT: bookmark this page if you plan on taking any Step 1 NBMEs (PC: “Ctrl + D,” Mac: “Command + D”).

Why is it useful to know what you would have scored on Step 1, even if it’s pass-fail now? Because as we’ve discussed before, Step 1 was the single-best predictor of Step 2 CK scores. And given how important Step 2 CK is becoming in residency applications, it’s useful to know your trajectory so you can course-correct.

NOTE 2/5/2023: new NBME score converters were added for NBME (CBSSA) 18-25. (AKA the old “retired” NBMEs).

Table of Contents

How to Use the NBME Step 1 Score Converter

To use our NBME score conversion tool, all you have to do is count the number of questions you missed. To do so, first click “View Your Results Interactively.”

Finally, enter the number of questions you got incorrect into the NBME Score Converter. The score conversion tool will convert it to your predicted Step 1 score.

NBME (CBSSA) 25 to Step 1 Score Converter

Each question on Step 1 CBSSA 25 is worth 1.05 points.

To get a 250 on CBSSA 25, you could only miss 21 questions.

NBME (CBSSA) 26 to Step 1 Score Converter

Each question on Step 1 CBSSA 26 is worth 1.11 points.

To get a 250 on CBSSA 26, you could only miss 23 questions.

NBME (CBSSA) 27 to Step 1 Score Converter

Like CBSSA 26, each question on Step 1 CBSSA 27 is worth 1.11 points.

To get a 250 on CBSSA 27, you could only miss 23 questions.

NBME (CBSSA) 28 to Step 1 Score Converter

Each question on Step 1 CBSSA 28 is worth 1.05 points.

To get a 250 on CBSSA 28, you could only miss 23 questions.

NBME (CBSSA) 29 to Step 1 Score Converter

Each question on Step 1 CBSSA 29 is worth 1.09 points.

To get a 250 on CBSSA 29, you could only miss 23 questions.

NBME (CBSSA) 30 to Step 1 Score Converter

Each question on Step 1 CBSSA 30 is worth 1.15 points. It is widely considered to be the most challenging NBME, and the best-fit line backs that up.

To get a 250 on CBSSA 30, you could only miss 24 questions.

CBSSA 18-24 (Retired) NBME Score Converter

For historical purposes, here are calculators for previous (retired) NBMEs 18-24. Note that CBSSA 19 was known for being particularly inaccurate, so treat those results with particular care. For what it is worth, CBSSA 18 was considered to be one of the most accurate of the NBMEs at that time.

NBME (CBSSA) 18 to Step 1 Score Converter

NOTE: NBME (CBSSA) 18 is retired. Each question on Step 1 CBSSA 18 is worth 1.06 points. It was widely considered the most accurate NBME of its cohort.

NBME (CBSSA) 19 to Step 1 Score Converter

NOTE: NBME (CBSSA) 19 is retired. Each question on Step 1 CBSSA 19 is worth 1.39 points. It was widely considered the LEAST accurate NBME of its cohort. This inaccuracy is likely the reason why it was retired before NBME 18, despite having been released later.

NBME (CBSSA) 20 to Step 1 Score Converter

NOTE: NBME (CBSSA) 20 is retired. Each question on Step 1 CBSSA 20 is worth 1.02 points.

NBME (CBSSA) 21 to Step 1 Score Converter

NOTE: NBME (CBSSA) 21 is retired. Each question on Step 1 CBSSA 21 is worth 1.02 points.

NBME (CBSSA) 22 to Step 1 Score Converter

NOTE: NBME (CBSSA) 22 is retired. Each question on Step 1 CBSSA 22 is worth 0.985 points.

NBME (CBSSA) 23 to Step 1 Score Converter

NOTE: NBME (CBSSA) 23 is retired. Each question on Step 1 CBSSA 23 is worth 1.04 points.

NBME (CBSSA) 24 to Step 1 Score Converter

NOTE: NBME (CBSSA) 24 is retired. Each question on Step 1 CBSSA 24 is worth 1.03 points.

Step 1 Passing Score Percentage

What is the Step 1 passing score percentage? We won’t know with certainty. However, we can determine what percentage you would need on each CBSSA (NBME) to pass Step 1.

The passing score percentage for each of the Step 1 NBMEs is:

• CBSSA 25 – 64% correct (73 incorrect)
• CBSSA 26 – 64% correct (72 incorrect)
• CBSSA 27 – 65% correct (71 incorrect)
• CBSSA 28 – 63% correct (75 incorrect)
• CBSSA 29 – 64% correct (72 incorrect)
• CBSSA 30 – 65% correct (71 incorrect)

Assuming Step 1 is scored similarly to CBSSA 25-30, you would need somewhere between 63 to 65% correct to attain the passing score of 196.

How Much Is Each Step 1 NBME Question Worth?

Points per question on CBSSA:

• 25: 1.05 point/question
• 26: 1.11 point/question
• 27: 1.11 point/question
• 28: 1.05 point/question
• 29: 1.09 point/question
• 30: 1.15 point/question

Average points/question for CBSSA 25-30 = 1.09 points

How Many Points is Each Step 1 Question Worth?

The NBME has never stated how many points each question is worth on Step 1. That said, we can make an educated guess on how much each question is worth, to know how close/far away you are/were to passing.

Let’s start with the average points/question of CBSSA 25-30 of 1.09. A Step 1 NBME has 200 questions, while Step 1 has 280 questions. If every single question on Step 1 was worth the same amount, then each question might be worth 1.09 * 200/280 = 0.78 points/question.

Note it has been speculated that up to 25% (80 questions) of Step 1 is “experimental” and won’t contribute to your score. If that were true, then we could assume that each Step 1 question may be close to the 1.09 point/question average for CBSSA 25-30.