Working out wire size for load

[Corgie Carrier]

Having a bit of a brain fart tonight and can't remember the formula to work out the wire size for the lights I want to install.

The led lights are 27w @ 12v

My brain is telling me that if I divide 27 by 12 it will give me 2.25amps. So I should be fine with 2mm/10amp wire.

Is this correct or have I mucked it up somehow?

How do I work out how much loss I get over distance?

From the fuse box to the switch then to the light will be about 5-6 metres.

Should I get 3mm wire?

Thanks in advance [thumbsupbig]

[Vern]

Correct in your maths. But you will have volt drop, i'd go 3mm.

[theelms66]

Correct in your maths. But you will have volt drop, i'd go 3mm.And a relay to reduce VD again.

[chrisbbarnes]

Download the Blue Sea Systems app. You can enter in all your parameters and it will tell you the size you should be using.