# Encyclopedia Magnetica

### Site Tools

calculator:current_loop_axis

### Calculator of H along axis of circular current loop

This section is an interactive calculator.
Magnetic field strength H of a circular current loop along its axis
$$H(t,x) = I(t) · \frac{1}{2}· \frac{r^2}{(x^2 + r^2)^{3/2}}$$ (A/m)
where: $I(t)$ - current (A) at time $t$ (s), $r$ - radius of the loop (m), $x$ - location (m) from the centre of the loop (the centre is located at point x = 0); assuming infinitely thin wire and a circular loop placed in a uniform medium
Current I =        Radius r =

Position on axis x =

H (A/m) =