How to Curve Grades in Canvas LMS: Step-by-Step Guide

Canvas LMS is one of the most widely used learning management systems in schools and universities. While Canvas offers a basic built-in grading feature for quizzes, many instructors find it limited. The native Canvas curve tool automatically changes student scores based on an average target score, but it does not support popular curving methods like the square root curve or standard deviation bell curves. It also modifies original student entries directly, which can make it hard to track raw performance.

This guide explains how Canvas handles curved grades, why copying scores into a specialized calculator is often the safest choice, and how to curve assignment scores accurately using external curving tools.

Native Canvas Curving vs. External Curving

Before adjusting scores, it helps to understand how Canvas handles grade curving natively versus using an external calculator.

Native Canvas Gradebook Curving

Canvas includes a built-in feature called Curve Grades for numeric assignments and quizzes.

Here is how the built-in Canvas tool works:

• You enter a desired target average score for the assignment.
• Canvas calculates the difference between the target average and the actual class average.
• Canvas adjusts student scores upward or downward to match that target score.

Limitations of the Native Canvas Tool

• Permanent Overwrites: Canvas overwrites the original raw scores in the gradebook. While you can view submission history, restoring raw scores across an entire class requires manual work.
• Limited Curving Methods: Canvas only supports a basic mean-matching curve. It does not support a Texas root curve (10 × √Raw), a linear percentage scale, or a standard deviation distribution.
• No Un-Curving Button: Once applied, you cannot simply toggle the curve off with one click.

External Curving (Copy-Paste Method)

Copying raw scores from Canvas into a specialized online calculator provides much more control:

• Preserves Raw Scores: You can keep the original raw assignment column untouched and create a separate column for curved grades.
• Access to All Curving Formulas: You can apply a square root curve, flat point addition, max-score scaling, or a bell curve based on mean and standard deviation.
• Full Transparency: Students can see both their original raw score and their final curved score in Canvas.

Step-by-Step Guide: How to Curve Canvas Grades Safely

Follow these five steps to export your Canvas gradebook scores, calculate curved grades accurately using our copy-paste calculator, and upload the updated results back into Canvas.

Step 1: Export Your Canvas Gradebook

1. Log in to Canvas and select your course.
2. Click Grades in the course navigation menu on the left.
3. In the top toolbar of the Gradebook, click Actions.
4. Select Export from the drop-down menu.
5. Canvas will generate a CSV file containing your student roster, student IDs, and all assignment columns. Download and save this file to your computer.

Step 2: Open the CSV File and Copy Raw Scores

1. Open the downloaded CSV file using Microsoft Excel, Google Sheets, or any spreadsheet software.
2. Locate the column for the assignment you want to curve (for example, Midterm Exam).
3. Select and copy the list of student raw percentage scores or points.

Tip: If you prefer using spreadsheets directly for basic math, you can also review our guides on how to curve grades in Excel and how to curve grades in Google Sheets.

Step 3: Paste Scores into the Grade Curve Calculator

1. Open the online Grade Curve Calculator.
2. Paste your copied list of raw student scores directly into the input text box (or enter scores row-by-row using the manual editor).
3. Choose the curving method that fits your instructional goals:
   • Square Root Curve (Texas Curve): Formula is 10 × √Raw Score. This boosts lower scores significantly while giving smaller increases to high scores.
   • Flat Point Shift: Adds a fixed number of points (such as +5 or +10 points) to every student’s score.
   • Linear Scale (Max Score Scaling): Scales scores based on the highest score in the class using (Raw Score ÷ Highest Score) × 100.
   • Standard Deviation Bell Curve: Adjusts scores using class mean ($\mu$μ) and standard deviation ($\sigma$σ) to fit letter grade brackets (A, B, C, D, F).
4. Click Calculate. The calculator instantly generates summary class statistics, visual charts, and a table of curved student scores.

Step 4: Export or Copy Curved Scores to Your Spreadsheet

1. Below the calculator results, click Export CSV (or click Copy Table to Clipboard).
2. Open your gradebook spreadsheet file in Excel or Google Sheets.
3. Create a new column next to your original raw scores. Name it clearly, such as Midterm Exam (Curved).
4. Paste the curved scores into this new column, ensuring each score matches the correct student row.
5. Save the updated file as a CSV format.

Step 5: Import the Curved Scores Back into Canvas

1. Return to your Canvas Gradebook.
2. Click Actions in the top Gradebook toolbar.
3. Select Import.
4. Click Choose File, select your updated CSV file, and click Upload Data.
5. Canvas will display a preview screen showing the new column. Confirm that the new assignment column is detected properly.
6. Click Save Changes. Canvas will add the new curved grade column to your gradebook.

Choosing the Right Curving Method for Your Canvas Course

Different assignment types call for different score adjustment strategies. Here is how popular curving methods compare when applied to classroom grades:

Curving Method	Formula	When to Use in Canvas	Impact on Student Scores
Square Root Curve	10 × √Raw Score	Hard exams where failing scores need support without pushing top scores past 100%.	Large boost to low scores (+21 pts on a 49), small boost to high scores (+2.5 pts on a 95).
Flat Point Shift	Raw Score + Fixed Points	Minor test corrections or when 1-2 questions were written poorly.	Equal point gain for all students. Can push top scores over 100% unless capped.
Linear Max Score Scale	(Raw ÷ Top Score) × 100	Tests where the highest scoring student earned an 88% instead of 100%.	Scales all scores proportionally so the top score becomes 100%.
Standard Deviation Bell Curve	Based on Mean ($\mu$μ) and Std Dev ($\sigma$σ)	Large courses (100+ students) requiring standardized grade distributions.	Assigns grades based on relative distance from class average.

To learn more about when score adjustments are appropriate, read our detailed guide on when teachers should curve grades.

Best Practices for Curving Grades in Canvas

To maintain academic integrity and prevent student confusion, follow these best practices when posting curved grades in Canvas:

• Keep Original Scores Intact: Never overwrite original raw submissions if you can avoid it. Creating a separate curved grade column lets students see both their raw performance and their curved score.
• Mute Assignment Notifications: Mute the assignment in Canvas before uploading updated grades (Gradebook > Assignment Settings > Grade Posting Policy > Manual). This prevents Canvas from sending multiple grade update notifications to students while you are importing CSV data.
• Explain the Curving Formula: Publish a short announcement in Canvas explaining which curving method was used and why. Transparent grading builds trust and reduces grade dispute inquiries.
• Check Institutional Policies: Some departments or universities have specific rules about whether grades can be adjusted. Review your school handbook or read our analysis on whether grading on a curve is fair.

Common Questions About Canvas Grade Curving