Every length of wire has a small resistance that adds up on long runs and heavy loads, and this calculator works it out for you. The resistance equals the material resistivity times the length divided by the cross sectional area. Pick copper, aluminium, silver or gold from the material list to load the correct resistivity, enter the wire length in metres and its cross section in square millimetres, and the tool returns the total resistance of the conductor. This matters for choosing a cable that will not overheat or drop too much voltage, for sizing battery leads, and for understanding losses in long extension runs. Because thicker wire has more area, doubling the cross section roughly halves the resistance, while doubling the length doubles it. Enter your numbers and read the answer instantly. Everything runs locally in your browser, so it is fast and private.
Every length of wire has a small resistance that adds up on long runs and heavy loads, and this calculator works it out for you. The resistance equals the material resistivity times the length divided by the cross sectional area.
Yes. Wire Resistance Calculator is completely free, with no sign-up and no usage limits.
Yes. Wire Resistance Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Wire Resistance Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.