Abstract: A very high speed counter system of operating at frequencies of up to around 800 MHz provides timing measurements with accuracies on the order of (1/f) seconds where f is the frequency of operation. The least significant bit of the counter operates at the given frequency of a first clock signal while the other higher order bits operate at a second clock signal where the second clock signal is one-half the frequency of the first clock signal and is inverted. Carry lookahead circuits connected between stages of the second counter operate in conjunction with the clocking scheme to produce a high speed and accurate counter.