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Magnetic Field Strength Converter

Science

Convert magnetic field strength (H field) between amperes per metre and oersted instantly — distinct from magnetic flux density (Tesla/Gauss).

Reviewed by the thecalcu.com team · Last updated July 6, 2026

From
To
All conversionsfor 1 Oersted (Oe)
Kiloamperes per Metre (kA/m)0.0795775
Amperes per Metre (A/m)79.5775
Oersted (Oe)1

What is a Magnetic Field Strength?

The Magnetic Field Strength Converter converts magnetic field strength (the H field) between amperes per metre, kiloamperes per metre (SI), and oersted (the legacy CGS unit). Magnetic field strength measures the magnetizing force applied to create a magnetic field, distinct from magnetic flux density (the B field), which the existing Magnetic Field Converter covers, and which measures the resulting field within a material.

Enter a value in any supported unit and the converter calculates the equivalent instantly. For the related driving-force quantity, see the Magnetomotive Force Converter.

Why Use a Magnetic Field Strength Converter?

Permanent magnet and magnetic recording media specifications frequently report coercivity and field strength in oersted (a long-standing industry convention), while modern SI-based engineering calculations use amperes per metre. Comparing a material's coercivity rating against a design's applied field strength requires accurate conversion between these unit systems.

Who Should Use This Converter?

  • Permanent magnet manufacturers and engineers working with coercivity specifications given in oersted.
  • Electromagnet and solenoid designers calculating applied field strength for magnetic circuit design.
  • Materials scientists researching magnetic properties across CGS and SI unit conventions.
  • Magnetic recording media engineers working with legacy oersted-based specifications.

What Insights Does the Magnetic Field Strength Converter Give You?

The main output is the converted value in your chosen target unit, calculated precisely from the fixed multiplier relationship between units. Remember that magnetic field strength (H) is distinct from magnetic flux density (B) despite the similar-sounding names, this converter handles the applied magnetizing force, not the resulting field within a material.

How to use this Magnetic Field Strength calculator

  1. Choose your starting unit from the source dropdown, for example, "Oersted (Oe)".
  2. Enter the numeric value you want to convert in the input field.
  3. Choose your target unit from the destination dropdown, for example, "Amperes per Metre (A/m)".
  4. Read the converted result, which updates instantly as you type or change units.
  5. Use the swap (⇅) button if you need to reverse the conversion direction.
  6. Use the copy button to grab the result for a magnet specification comparison or electromagnet design calculation.
Show formula & methodology ↓Show less ↑

Formula & Methodology

The converter's base unit is amperes per metre (A/m). Every supported unit has a fixed multiplier:

- 1 kiloampere per metre (kA/m) = 1,000 A/m
- 1 oersted (Oe) ≈ 79.5775 A/m

Any conversion follows:

Result = Input × (toBase of source unit ÷ toBase of target unit)

Worked example, converting a permanent magnet's coercivity of 12,000 Oe to kA/m:

Result = 12,000 × (79.5775 ÷ 1,000) = 954.93 kA/m

This is the SI-unit equivalent you'd use in a modern engineering calculation involving that magnet's coercivity.

Related Tools

You may also find these useful: Magnetic Flux Converter.

Frequently Asked Questions

What is magnetic field strength, and how is it different from magnetic flux density?
Magnetic field strength (the H field, in amperes per metre) measures the magnetizing force applied to create a magnetic field, while magnetic flux density (the B field, in Tesla or Gauss, covered by the existing [Magnetic Field Converter](/magnetic-field-converter/)) measures the resulting magnetic field within a material. The two are related by the material's magnetic permeability, and are equal in a vacuum but can differ significantly inside magnetic materials.
How do I convert oersted to amperes per metre?
Multiply the oersted value by 79.5775, since one oersted equals approximately 79.5775 amperes per metre. Enter your value with 'Oersted (Oe)' as the source and 'Amperes per Metre (A/m)' as the target to apply this automatically.
Why is oersted still commonly used for magnetic materials specifications?
Oersted (the CGS unit) remains the conventional unit for specifying coercivity and other magnetic material properties in many industries, particularly for permanent magnets and magnetic recording media, due to long-standing convention even though SI units are the modern scientific standard.
How does magnetic field strength relate to magnetomotive force?
Magnetic field strength equals magnetomotive force divided by the length of the magnetic path (H = MMF/length), field strength is MMF distributed along a specific path, while MMF is the total driving force. See the [Magnetomotive Force Converter](/magnetomotive-force-converter/) for that related quantity.
What is coercivity, and how is it measured?
Coercivity is the magnetic field strength required to reduce a magnetized material's magnetization to zero, commonly specified in oersted for permanent magnet materials, a higher coercivity indicates a magnet more resistant to demagnetization.
What is a typical magnetic field strength value inside a solenoid?
This depends entirely on the solenoid's winding density (turns per unit length) and current, a solenoid with 1,000 turns per metre carrying 1 amp produces a field strength of 1,000 A/m, and the value scales directly with both factors.
How does magnetic field strength relate to magnetic flux density in a vacuum?
In a vacuum (or air, approximately), magnetic flux density (B) equals magnetic field strength (H) multiplied by the permeability of free space, a fixed constant, making the two values proportional in non-magnetic environments, though they diverge significantly inside ferromagnetic materials.
Why do magnetic material datasheets specify both H and B field values?
Ferromagnetic materials respond non-linearly to an applied field, so datasheets typically show a full B-H curve (hysteresis loop) rather than a single conversion factor, since the relationship between applied field strength and resulting flux density depends on the material's magnetic history and saturation behaviour.
What industries commonly need magnetic field strength unit conversion?
Permanent magnet manufacturing, magnetic recording media design, electromagnet and solenoid engineering, and materials science research into magnetic properties all routinely work with magnetic field strength data, often needing conversion between the SI A/m and legacy CGS oersted units.
Is magnetic field strength the same everywhere inside a magnetic circuit?
No, magnetic field strength can vary at different points within a magnetic circuit, particularly at boundaries between materials with different permeabilities, which is why magnetic circuit analysis often requires calculating field strength separately for each segment of the path.
Also known as
magnetic field strength convertera/m to oersted converterh field converteroersted to a/m convertermagnetizing force converter