Fidamen

Convert Gradians to Mils - Angle Converter

This tool converts angles expressed in gradians (also called grads or gons) into mils. By default it uses the common 6400‑mils‑per‑circle definition (often used in NATO mapping), which yields a simple fixed ratio: 1 gradian = 16 mils.

Gradians divide a full circle into 400 units while the 6400‑mil system divides a full circle into 6400 units; the conversion is exact under that definition. If you require a different mil definition (for example, artillery systems that use 6000 mils per circle), consult the FAQ and use an alternate converter that matches your instrument's specification.

Where measurement traceability matters (surveying, munitions, metrology), follow laboratory calibration and SI guidance from standards authorities to ensure results meet regulatory or contractual tolerances.

Updated Nov 10, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record 28cc5f7487d1 • Reviewed by Fidamen Standards Committee

Interactive Converter

Convert between gradian and mil with precision rounding.

Quick reference table

GradianMil
1 gradMIL 16.00 mil
5 gradMIL 80.00 mil
10 gradMIL 160.00 mil
25 gradMIL 400.00 mil
50 gradMIL 800.00 mil
100 gradMIL 1,600.00 mil

Methodology

We base the conversion on circle subdivisions: 1 full revolution = 400 gradians = 6400 mils (for the 6400‑mil convention). Dividing both sides by 400 gives 1 gradian = 16 mils.

This converter uses the fixed mathematical relationship implied by those subdivisions. For traceable measurement practice, consult national metrology guidance (for example, NIST) and the SI Brochure for conventions and notation.

Note on variants: some organizations and older artillery tables use 6000 mils per circle. That alternative changes the numeric ratio (1 gradian = 15 mils if 6000 per circle). Verify which mil definition your workflow or instrument requires before applying results in operational contexts.

Worked examples

Convert 25 gradians to mils: 25 × 16 = 400 mils (6400‑mil convention).

Convert 7.5 gradians to mils: 7.5 × 16 = 120 mils.

Convert 320 mils to gradians: 320 ÷ 16 = 20 gradians.

F.A.Q.

Which definition of 'mil' does this converter use?

This converter uses the 6400‑mils‑per‑circle convention (commonly used in NATO mapping and many surveying contexts). If your application or equipment specifies a different mil definition (for example, 6000 per circle), use a converter or calculation that matches that definition because the numeric factor changes (1 gradian = 16 mils under 6400; 1 gradian = 15 mils under 6000).

How exact is the conversion?

The relationship 1 gradian = 16 mils is exact under the 6400‑mil convention because both are integer subdivisions of a full circle. Numerical rounding only occurs when you display results to a limited number of decimal places; choose precision consistent with your instrument and tolerance requirements.

Can I rely on this for surveying or ordnance applications?

You can use this converter for quick calculations, but for regulatory, legal, or safety‑critical tasks follow instrument calibration records and traceability procedures. Verify the mil definition used by your field equipment and confirm tolerances with your organization's metrology or QA documentation. Consult national metrology guidance (for example, NIST) for traceability recommendations.

How should I handle rounding and display precision?

Match rounding to the resolution of the measurement device and the downstream use case. For example, if your theodolite or digital compass reports to 0.1 gradians, show results with an equivalent or slightly higher precision in mils (e.g., one or two decimal places). Avoid overstating precision beyond instrument capability.

How can I verify instrument calibration?

Follow your laboratory or instrument vendor procedure for angular calibration. Trace calibration to a recognized metrology lab or national metrology institute and retain certificates. For general SI and metrology guidance refer to national standards bodies.

Sources & citations

Further resources

Versioning & Change Control

Audit record (versions, QA runs, reviewer sign-off, and evidence).

Record ID: 28cc5f7487d1

What changed (latest)

v1.0.0 • 2025-11-10 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Public QA status

PASS — golden 25 + edge 120

Last run: 2026-01-23 • Run: golden-edge-2026-01-23

Engine

v1.0.0

Data

Baseline (no external datasets)

Content

v1.0.0

UI

v1.0.0

Governance

Last updated: Nov 10, 2025

Reviewed by: Fidamen Standards Committee (Review board)

Credentials: Internal QA

Risk level: low

Reviewer profile (entity)

Fidamen Standards Committee

Review board

Internal QA

Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person

Semantic versioning

  • MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
  • MINOR: New features or fields that do not change existing outputs for the same inputs.
  • PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.

Review protocol

  • Verify formulas and unit definitions against primary standards or datasets.
  • Run golden-case regression suite and edge-case suite.
  • Record reviewer sign-off with credentials and scope.
  • Document assumptions, limitations, and jurisdiction applicability.

Assumptions & limitations

  • Uses exact unit definitions from the Fidamen conversion library.
  • Internal calculations use double precision; display rounding follows the unit's configured decimal places.
  • Not a substitute for calibrated instruments in regulated contexts.
  • Jurisdiction-specific rules may require official guidance.

Change log

v1.0.0 • 2025-11-10 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: 8155d681111b