Calculate magnetic pressure from field strength or find magnetic field strength from pressure in Pa, psi, bar, atm, T, G, or mT units.
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Magnetic Pressure Formula
The magnetic pressure calculator uses the magnetic pressure relationship for a magnetic field in free space, using the permeability of free space as a fixed constant.
- P = magnetic pressure, in pascals (Pa) in the base calculation
- B = magnetic field strength, in tesla (T) in the base calculation
- μ0 = permeability of free space, 1.2566370614 × 10-6 H/m
If you enter magnetic field strength, the calculator finds magnetic pressure using P = B2 / (2μ0). If you enter magnetic pressure, it rearranges the same equation to find magnetic field strength using B = √(2Pμ0).
The calculator converts your selected units to base SI units before calculating, then converts the result back to the unit selected for the missing value.
Magnetic Pressure Unit Conversions
These are the unit conversions used before and after the main calculation.
| Pressure unit | Equivalent in pascals |
|---|---|
| 1 Pa | 1 Pa |
| 1 psi | 6,894.76 Pa |
| 1 bar | 100,000 Pa |
| 1 atm | 101,325 Pa |
| Magnetic field unit | Equivalent in tesla |
|---|---|
| 1 T | 1 T |
| 1 mT | 0.001 T |
| 1 G | 0.0001 T |
Example Calculations
Example 1: Calculate magnetic pressure from magnetic field strength
Suppose the magnetic field strength is 2 T.
The magnetic pressure is approximately 1,591,549.43 Pa.
Example 2: Calculate magnetic field strength from magnetic pressure
Suppose the magnetic pressure is 100,000 Pa.
The magnetic field strength is approximately 0.5013 T.
FAQ
What does magnetic pressure mean?
Magnetic pressure is the pressure associated with a magnetic field. It describes the energy density effect of the field and is commonly expressed in pascals. A stronger magnetic field gives a much larger magnetic pressure because the pressure is proportional to the square of the magnetic field strength.
Why does the calculator use μ0?
The calculator uses μ0, the permeability of free space, because the formula shown is for a magnetic field in vacuum or air approximated as free space. If you are working in a material with a different magnetic permeability, the result may not match the real physical pressure in that material.
Why can I only enter one value?
The calculator is designed to solve for the missing variable. Enter magnetic field strength to calculate magnetic pressure, or enter magnetic pressure to calculate magnetic field strength. If both fields are filled, the calculator cannot know which value you want it to solve for.