Metric holds an advantage in simplicity, but imperial seems to have better unit amounts. For instance, temperature. I cannot think in celcius. 60's weather is 15-20 celcius. 70's is 20-26 celcius. 80's weather is 27-34 celcius. Lengths: a mile is a significant accomplishment for human endurance. A kilometer is barely enough to get your heartbeat up. Weights. having to say 1800 kilograms instead of saying 2 tons is unwieldy, and is . Tons seems right because they indicate when you've reached industrial capacities. Liquid. Gallons vs liters. A gallon seems to be a substantial amount of liquid, while a liter is basically too small to really be of substantial measure, and too big for personal consumption compared to the pint. Even when calculating like interstellar distances, any advantage from metric is going to be non-existent because the unit you're using will either be miles or kilometers and there won't be much conversion to other units going on. Or, for microscopic measurements, you could probably use micro-inches as a measure just as easily as nano-meters are commonly used today.