Convert Radians (rad) to Milliradians (mrad)

1 radian equals 1000 milliradians.

Formula: mrad = rad × 1000

Radian to Milliradian Converter

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How to Convert Radian to Milliradian

1 radian = 1000 milliradians

Milliradian = Radian × 1000

Example: 1 rad × 1000 = 1000 mrad

Reverse Conversion

To convert milliradians back to radians:

  • Remember, 1 milliradian equals 0.001 radians.
  • To convert 1000 mrad to rad, multiply 1000 x 0.001, resulting in 1 rad.

Common Radian to Milliradian Conversions

Radian to Milliradian (Part 1)
Radian Milliradian Actions
0.001 radians 1 milliradian
0.01 radians 10 milliradians
0.1 radians 100 milliradians
12 radians 500 milliradians
Radian to Milliradian (Part 2)
Radian Milliradian Actions
1 radian 1000 milliradians
3.14159 radians 3141.59 milliradians
6.28318 radians 6283.18 milliradians

Radians to milliradians Conversion Table

Reference table with common radians to milliradians conversions. All values calculated with high precision.

Radians to Milliradians Table
0.0001 to 12

Radians Milliradians Actions
0.0001 rad 0.1 mrad
0.00025 rad 14 mrad
0.0005 rad 12 mrad
0.001 rad 1 mrad
0.0025 rad 12 mrad
0.005 rad 5 mrad
0.01 rad 10 mrad
0.025 rad 25 mrad
0.05 rad 50 mrad
0.1 rad 100 mrad
14 rad 250 mrad
12 rad 500 mrad

Radians to Milliradians Table
1 to 100000

Radians Milliradians Actions
1 rad 1000 mrad
12 rad 2500 mrad
5 rad 5000 mrad
10 rad 10000 mrad
25 rad 25000 mrad
50 rad 50000 mrad
100 rad 100000 mrad
250 rad 250000 mrad
500 rad 500000 mrad
1000 rad 1000000 mrad
2500 rad 2500000 mrad
5000 rad 5000000 mrad
10000 rad 10000000 mrad
25000 rad 2.5 × 107 mrad
50000 rad 5 × 107 mrad
100000 rad 1 × 108 mrad

Milliradians to Radians Table
0.1 to 500

Milliradians Radians Actions
0.1 mrad 0.0001 rad
14 mrad 0.00025 rad
12 mrad 0.0005 rad
1 mrad 0.001 rad
12 mrad 0.0025 rad
5 mrad 0.005 rad
10 mrad 0.01 rad
25 mrad 0.025 rad
50 mrad 0.05 rad
100 mrad 0.1 rad
250 mrad 14 rad
500 mrad 12 rad

Milliradians to Radians Table
1000 to 1 × 108

Milliradians Radians Actions
1000 mrad 1 rad
2500 mrad 12 rad
5000 mrad 5 rad
10000 mrad 10 rad
25000 mrad 25 rad
50000 mrad 50 rad
100000 mrad 100 rad
250000 mrad 250 rad
500000 mrad 500 rad
1000000 mrad 1000 rad
2500000 mrad 2500 rad
5000000 mrad 5000 rad
10000000 mrad 10000 rad
2.5 × 107 mrad 25000 rad
5 × 107 mrad 50000 rad
1 × 108 mrad 100000 rad

Definition of Radian

Definition

The radian (rad) is the SI derived unit of plane angle. It is defined as the angle subtended at the center of a circle by an arc equal in length to the radius.

Although mathematically dimensionless, the radian is retained as a named unit in the SI to preserve clarity in scientific, engineering, physics, trigonometry, and calculus contexts.

Exact factor
Base unit: 1 rad = 1 rad; full circle: 2π rad = 360°
Examples
  • π rad = 180°
  • 1 rad ≈ 57.2958°
  • 2π rad = 1 turn

Definition of Milliradian

Definition

The milliradian (mrad) is one thousandth of a radian.

It is widely used in ballistics, laser alignment, optical engineering, and instrumentation.

Exact factor
1 mrad = 0.001 rad
Examples
  • 1 mrad ≈ 0.0573°
  • 10 mrad = 0.01 rad

About the Radian

Facts & Uses

  • SI coherent unit of plane angle: 1 rad = the angle subtended at a circle's center by an arc equal in length to the radius. 1 full circle = 2π rad ≈ 6.283 rad.
  • Universal in mathematics, physics, engineering, and computer graphics — wherever calculus or trigonometric derivatives are involved.
  • Standard for angular velocity (rad/s), angular acceleration (rad/s²), and phase angles in electrical engineering and signal processing.
  • Common reference: π/6 rad = 30°, π/4 = 45°, π/3 = 60°, π/2 = 90°, π = 180°, 2π = 360°.

Curiosities

  • The radian was first proposed by Roger Cotes in 1714, but the name "radian" wasn't coined until 1873 by James Thomson (brother of Lord Kelvin).
  • Programming functions like Math.sin() and Math.cos() in JavaScript, Python, C, and most languages take radians as input — a frequent source of bugs for developers expecting degrees.
  • The reason calculus prefers radians: the derivative of sin(x) is cos(x) only when x is in radians. With degrees, you'd need a π/180 factor everywhere.
  • Approximate equivalents: 1 rad ≈ 57.2958° ≈ 63.66 grad ≈ 3437.75 arcminutes.

Sources

About the Milliradian

Facts & Uses

  • 1 milliradian (mrad) = 0.001 rad ≈ 0.0573° ≈ 3.438 arcminutes. The metric milliangular unit, distinct from the NATO mil (1/6400 vs 1/6283).
  • Standard for laser pointing (beam divergence in mrad), optical instrumentation, and European precision shooting.
  • Used in physics experiments for small-angle measurements, gyroscopic instruments, and servo positioning in robotics.
  • Convenient for far-field beam quality: a typical laser pointer beam diverges 0.5-1.5 mrad, a HeNe laser ~1 mrad, a high-power industrial laser <0.1 mrad.

Curiosities

  • 1 mrad subtends 1 m at 1000 m distance exactly — making it a natural unit for sniper range estimation in metric systems (similar to the NATO mil approximation).
  • The milliradian and the NATO mil are NOT identical: 1 mrad ≈ 1.018 NATO mils. The 1.8% difference matters for long-range artillery and scientific instruments.
  • Telescope eyepiece field-of-view is often spec'd in mrad for astronomical use — useful when calculating sky-tracking rates for astrophotography.
  • Approximate equivalents: 1 mrad = 0.001 rad ≈ 0.0573° ≈ 3.438 arcminutes ≈ 1.018 NATO mils.

Sources

Frequently Asked Questions

How many milliradians are in one radian?

One radian equals 1000 milliradians. To convert, multiply the radian value by 1000. For the reverse, divide the milliradian value by 1000 (or multiply by 0.001).

What is 10 radians in milliradians?

10 radians = 10000 milliradians. This is one of the most commonly searched conversions for this pair.

Is the radian-to-milliradian conversion exact?

Yes. The factor 1000 is exact by international definition, not an approximation. Any imprecision comes only from the original measurement, not the conversion.

Looking for the reverse? Convert Milliradian to Radian

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Conversion factors verified against BIPM, ISO 80000-3 1 turn = 2π rad = 360° (exact, ISO 80000-3). Last reviewed: March 2026
Tiago Fernandes Reviewed by Tiago Fernandes

All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.