Real-World Estimation

Walking speed: about 3 mph. Cycling: 12-15 mph. City driving: 25-30 mph effective (with lights and stops). Highway: 55-70 mph. Knowing these benchmark speeds lets you estimate arrival times without GPS. A 6-mile walk takes about 2 hours. A 30-mile city drive takes about an hour.

For international conversions: 1 mile ≈ 1.6 km, so 100 km/h ≈ 62 mph. A quick rule: divide km/h by 1.6 to get mph, or multiply mph by 1.6 to get km/h. With this single conversion factor, you can handle speed limits and distances in any country.