Using Your Scope Reticle for Range Estimation

Knowing your distance to the target is crucial for knowing how much holdover to give the target.

The easiest way to do this is to use a rangefinder, which generally provides an accurate measurement within about a yard or so.

But what happens if you don't have a laser rangefinder and need to know the distance? You use the reticle in your scope.

Range Estimation Using a Reticle

Using a rifle scope reticle to estimate distance is a technique often referred to as range estimation or milling, especially when using a Mil-Dot or MOA reticle.

This method is a quick way of measuring distance with the equipment you have. It is an estimation and not as accurate as a laser rangefinder, but generally accurate within about 5%.

MRAD Calculation

The calculation is simple, especially if you have an MRAD scope.

Distance (meters) = Target size (cm) × 10 ÷ Mils

Distance (yards) = Target size (inches) × 27.78 ÷ Mils

• Target size: The height or width of the target.
• Mils: The number of Mils (milliradians) the target spans in your reticle.
• 27.78: Conversion constant to get yards when using inches and mils.

Example – MRAD

Let's range a 66% IPSC target.

These targets are 20" by 12" (30.48cm by 50.0cm).

Width spans 1.18 mils, height spans 1.8 mils.

30.48cm × 10 ÷ 1.18 mils = 258.3 meters

50.8cm × 10 ÷ 1.8 mils = 282.2 meters

Average distance = (258.3 + 282.2) ÷ 2 = 270.25 meters

For yards:

12" × 27.78 ÷ 1.18 mils = 282.5 yards

20" × 27.78 ÷ 1.8 mils = 308.6 yards

Average distance = (282.5 + 308.6) ÷ 2 = 295.55 yards

MOA Calculation

With an MOA scope, the calculation is:

Distance (yards) = Target size (inches) × 95.5 ÷ MOA the target covers in the reticle

The 95.5 constant comes from how MOA works (1 MOA = 1.047 inches at 100 yards).

Example target: 18" wide × 24" high.

18" × 95.5 ÷ 1.8 MOA = 955 yards

24" × 95.5 ÷ 2.4 MOA = 955 yards

Shortened MRAD Method

Once familiar with the math, you can shorten it to:

Distance (meters) = Target size (millimeters) ÷ Mils

Example: 508mm ÷ 1.8 mils = 282.2 meters

This method is popular in Field Target and Hunter Field Target competitions where speed is essential.

Example: 12mm ÷ 1.5 mils = 8 meters

Tips for Accurate Estimation

• Always range at the correct magnification in Second Focal Plane scopes as the subtensions are only accurate at a certain magnification.
• Practice estimating target size accurately; errors will significantly affect range estimation.
• Use a range card or pre-measured target sizes for common game or silhouette targets to speed up field estimation.