The Proper Zeroing and Calibration Process for Red Dot Sights

Chris G.

Congratulations on purchasing your first red dot sight! You made the right decision! With a red dot sight, you can quickly and rapidly shoot at targets with satisfying accuracy. You’ll enjoy a better and more efficient shooting experience.

That is: if you properly calibrate your sight. Before using, it’s important to adjust the optic’s alignment to make sure that you hit your intended target each time you pull the trigger.

In this article, we will guide you on how to properly zero your sight, grasp the significance of MOA (Minute of Angle), and how to zero without firing your firearm. Ready to learn? 

Why You Should Zero a Red Dot Optic

a man zeroing on a target

Your red dot sight may be useful right off the bat. You might be tempted to simply mount it on your firearm and fire away. But wait! Do red dot sights need to be adjusted? Even brand new ones? The answer is a big yes. You need to calibrate—or zero—your red dot first. 

  1. Align Point of Aim with Point of Impact: Zeroing allows you to align the point of aim (where you’re aiming) with the point of impact (where the bullet hits). This ensures that your shots land where you intend.
  2. Compensate for Bullet Trajectory: Different firearms, ammunition types, and distances can affect the trajectory of bullets. Zeroing adjusts the sight to compensate for these variables.
  3. Optimal Engagement Range: Zeroing allows you to set the sight for an optimal engagement range. For example, a common zeroing distance for rifles is 100 yards, providing a good balance for various distances for this particular firearm.
  4. Consistency Across Different Firearms: Zeroing ensures consistency if you use the same red dot sight on different platforms.
  5. Different Shooting Conditions: Zeroing allows you to account for variations in shooting conditions, such as wind, elevation, and temperature. A properly zeroed red dot sight improves shot placement in diverse environments.
  6. Adapt to Your Shooting Style: Each shooter has a unique shooting style or stance. Zeroing allows you to adapt the red dot sight to your specific style, ensuring the reticle is aligned with your natural point of aim.
  7. Confidence in Shot Placement: Knowing that your red dot sight is properly zeroed instills confidence in your ability to place shots accurately. 
  8. Prevent Wasted Ammunition: Zeroing helps avoid wasted ammunition by ensuring that your shots are consistently on target. 
  9. Establishing a Baseline: Zeroing provides a baseline reference for your sight. This reference point allows you to make more informed adjustments if needed such as compensating for changes in ammunition or shooting conditions.
  10. Effective Use of Holds and Holds-Over: A properly zeroed red dot sight allows you to use holds and holds-over effectively, especially when shooting at distances beyond the zeroed range.

Effective Distance When Zeroing a Red Dot Sight

a man zeroing on a target

At what distance should I zero my red dot? The effective distance for zeroing a red dot sight depends on several factors including the type of firearm, the caliber of the ammunition, the intended use, and personal preferences. Common zeroing distances for red dot sights often fall within the range of 25 to 100 yards/meters, but the specific distance can vary based on individual needs and shooting scenarios. 

  1. Short-Range Zero (25 Yards/Meters): A short-range zero is often suitable for firearms intended for close-quarters engagements. This is common for concealed carry pistols, full-size handguns, and SMGs used in home defense or law enforcement scenarios. It provides a point of impact close to the point of aim at short distances.
  2. Intermediate Range Zero (50 Yards/Meters): An intermediate range zero is a compromise that works well for a variety of applications. It offers good accuracy at both shorter and longer distances. This is a popular choice for carbines, AR-15-style rifles, and similar firearms.
  3. Mid-Range Zero (75 Yards/Meters): A mid-range zero is suitable for shooters who anticipate engagements at moderate distances. This zero provides a balance between short and long-range accuracy. It is often chosen by those who participate in practical shooting competitions or varmint hunting.
  4. Long-Range Zero (100 Yards/Meters): A long-range zero is commonly used for rifles intended for precision shooting and longer distances. This zero is often chosen for hunting, target shooting, and military applications. It allows for a flatter trajectory at extended ranges.

Beyond 100 yards/meters, the red dot becomes less accurate.

Step-by-Step Guide to Zero a Red Dot Sight

Zeroing a red dot sight is easy. It involves adjusting the sight so that the point of aim aligns with the point of impact at a specific distance. Here’s a step-by-step guide to help you zero your red dot sight:

Step 1: Gather Your Equipment

  • Firearm: Ensure it is unloaded and safe to handle.
  • Ammunition: Use the same type you plan to use regularly.
  • Shooting Rest or Stable Platform: For consistency.
  • Targets: Paper targets or target stickers.
  • Allen Wrench or Screwdriver: To make adjustments on the red dot sight.
  • Measuring Tape or Range Finder: To measure the shooting distance.

Step 2: Choose Zeroing Distance

Select the distance at which you want to zero your red dot sight. Common distances include 25, 50, 75, or 100 yards/meters, depending on your firearm and shooting preferences.

Step 3: Set Up the Target

Place the target at the chosen distance. Consider using a target with a clearly visible bullseye or aiming point.

Step 4: Fire a Group

Fire a group of shots (usually three to five rounds) at the center of the target while aiming at the chosen point of impact. Use a stable shooting position to minimize shooter-induced errors.

Step 5: Evaluate Group Placement

Examine where the shots landed in relation to the point of aim. If the group is consistently off-center, determine the direction and magnitude of the needed adjustments.

Step 6: Make Windage and Elevation Adjustments

Use the windage and elevation adjustment knobs on the red dot sight to move the point of impact. Adjust in the opposite direction of where you want the shots to go. For example:

  • Turn the windage knob left to move the point of impact left.
  • Turn the elevation knob up to move the point of impact up.

Step 7: Fire Another Group

Fire another group of shots to confirm the adjustments. Ensure a stable shooting position and maintain consistent aim.

Step 8: Repeat Adjustments if Necessary

If needed, repeat the process of making adjustments and firing groups until the shots consistently hit the desired point of impact.

Step 9: Confirm Zero at Different Distances

Verify your zero at distances other than the initial zeroing distance to ensure consistency. This step is important if your red dot sight has multiple brightness settings.

Step 10: Record Zeroing Data

Document your zeroing data, including the distance, type of ammunition, and any environmental conditions. This information will be useful for future reference.

Step 11: Fine-Tune as Needed

Fine-tune your zero as needed based on your shooting preferences and the specific requirements of your firearm and ammunition.

Step 12: Maintain and Recheck

Regularly check and maintain your zero, especially after changes in equipment or ammunition. Recheck the zero periodically to ensure accuracy.

Zeroing Your Red Dot Without Shooting

a man boresighting behind a red dot

Zeroing a red dot sight without shooting is possible. However, it may not be as precise or reliable as zeroing through live-fire. Even so, there may be times and situations where you need to calibrate your red dot sight without having to fire rounds. 

  1. Secure the Firearm: Ensure the firearm is unloaded, and the chamber is clear. Treat the firearm as if it were loaded.
  2. Mount the Firearm: Place the firearm in a stable shooting position, either using a gun vise or securing it on a shooting rest. This helps minimize movement during the zeroing process.
  3. Boresight the Red Dot Sight: Boresighting is the process of aligning the reticle of the red dot sight with the bore axis of the firearm. Use a laser boresighter or a boresighting tool designed for your specific firearm to achieve a rough alignment.
  4. Adjust Windage and Elevation: Look through the red dot sight and find a fixed point in the distance. Adjust the windage and elevation controls to move the reticle to align with that point. Use the turrets or adjustment knobs on the sight to make these adjustments.
  5. Use a Boresight Target: Some boresight tools come with target grids that help you make more precise adjustments. Place the target at a known distance, and use the grid lines to guide your adjustments for windage and elevation.
  6. Verify the Zero on a Static Object: Without shooting, you can verify the zero by aiming at a static object at a known distance. Ensure the red dot aligns with the point of aim. 
  7. Fine-Tune Adjustments: Make small adjustments to the windage and elevation controls as needed, continually verifying the alignment with the chosen point of aim.
  8. Use a Boresight Target with Grids: Continue to use a boresight target with grids to refine your adjustments. 
  9. Record Adjustments: Keep a record of the adjustments made to windage and elevation so that you can replicate or fine-tune the zero during live-fire confirmation.


Properly zeroing your red dot sight is an important step in ensuring precise and consistent shooting accuracy. By properly calibrating and adjusting your sight, you can confidently guarantee your shots will hit right where you intend them to.

About the author

The name's Chris. Just a regular dude who loves firearms. I've been shooting since I was a kid. My old man taught me the ropes.

I'll never forget the first time I missed an easy shot on a buck, thanks to a bum scope. The image was fuzzier than my dog's butt. After that, I got obsessed with understanding scopes. What makes the good ones tick and the bad ones trash. After a few years and a few thousand bucks, I learned what separates the winners from the losers. Once I had a good stockpile of knowledge, I launched this site.

Leave a Comment