How much amount of voltage is deadly?

The Voltage Is not deadly itself. Its how much current is flowing with it.

7 millliamps can kill you. Yes, that's milli, as in 1 thousanth of an amp. IF it toches your heart which is very unlikely. your skin acts as a resistor to resist that extra current.

Now you might be thinking, static electricity probably outputs way more then that every day, so how come were not all dead? This is because this amperage must be applied directly to the heart. Our whole body works as an insulator to electricity, weakening and most likely stopping the electricity before it gets to our heart (hopefully).

lightning bolts, carry around 1 billion volts. However, air dissapates 10000 volts of electrivity per centimetre. This mean for electricity to even get to your from 10 centimetres away through air, it requires 10000 volts. Lightning also needs to get past our clothes, which is probably wet in the event of a thunderstorm, spreading the electricity across the surface of the body, losing more energy. This is the main way lightning stroken people survive.

But still. If 7 milliamps touches your skin, youll be fine. LEDs work at 25-50milliamps. A house electrical main can kill .Now that can kill instantly