EVERYDAY CLARITY
Magnetic Field Calculator
What magnetic field surrounds a long straight wire carrying current? Enter the stated values to calculate this model.
Your result
Signed circumferential field
T
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Current (A) | Enter current in A; use the same basis as the other measurements. |
| Distance from wire (m) | Enter distance from wire in m; use the same basis as the other measurements. |
Understanding your result
Read Signed circumferential field (T) in the units and model stated on this page. The formula field=1.25663706127e-6*current/(2*pi*r) defines the relationship; measurement accuracy and model applicability are separate from numerical precision.
Common mistakes
- Mixing input units or changing the physical meaning of a variable without changing the model.
Check your calculation
- Use the worked example as a known reference case, then change one input at a time and check the direction and units of the response.
Calculation checks, sources and review limits
What magnetic field surrounds a long straight wire carrying current?
What magnetic field surrounds a long straight wire carrying current? Enter the stated values to calculate this model.
Common uses
- What magnetic field surrounds a long straight wire carrying current
How it works
field=1.25663706127e-6*current/(2*pi*r)
Worked example
Enter Current: 10 A; Distance from wire: 0.1 m. Results: Signed circumferential field: 0.000019999999997359664 T.