Resistor Colour Code Simulation

Carbon resistors are too small to print their values on, so they carry coloured bands. On a four-band resistor the first two bands are digits, the third is a power-of-ten multiplier and the fourth the tolerance; five-band (precision) resistors have three digits. The colours black to white stand for 0 to 9 — remembered as 'B B ROY of Great Britain had a Very Good Wife'.

This resistor colour code simulation lets you click the bands to change them and read the value, type a value to see its bands, and practise on randomly generated resistors with your score kept. A full table of colours, digits, multipliers and tolerances sits underneath.