Copper cable current Gauge calculation
The theoretical calculation of the wire's current carry capability is not that easy. It depends on factors like ambient temperature, the mounting conditions, the convection coefficient, the max allowed temperature of the insulation, the conductor's material and so on.

I recommend using a dimensioning table like this for the first indication.

The cross section of your strands can be easily calculated with
$$A_{Strand}=\left(\frac{d}{2}\right)^2\pi=\left(\frac{0.15}{2}\right)^2\pi=0.017mm^2$$

and the total cross section is
$$A_{total}=N\cdot A_{Strand}=8\cdot 0.017=0.141mm²$$

The lookup table suggests a maximum current of approx 2.2Amps for this cross section.