Speed Calculator
Enter your values below and click Calculate for instant results.
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Calculate speed, distance, or time from any two known values. Supports mph, km/h, and m/s.
Enter your values below and click Calculate for instant results.
Speed, distance, and time are related by a simple formula: speed equals distance divided by time. Knowing any two values lets you calculate the third. This calculator handles all three modes, making it useful for travel planning, fitness tracking, physics problems, and everyday estimation.
A quick rule of thumb for highway travel: at 60 mph, you cover exactly 1 mile per minute. At 65 mph, you cover about 1.08 miles per minute. At 70 mph, about 1.17 miles per minute. Knowing this makes mental ETA calculations easy on any road trip.
This calculator accepts input in miles, kilometers, or meters for distance, and mph, km/h, or m/s for speed. Results are shown in multiple units so you can use whichever is most meaningful for your situation. The speed of sound is approximately 767 mph or 1,235 km/h at sea level. The speed of light is about 186,282 miles per second or 299,792 km/s.