Travel Time Calculator

Travel time at constant speed is distance divided by speed. Use the same system for both inputs — miles with mph, or kilometers with km/h. The calculator also shows hours and minutes for quick reading.

Real trips include stops, traffic, toll delays, and route changes. For flights, use average ground speed (distance ÷ scheduled block time), not cruise speed alone — climb and descent add time.

Example: 420 miles at an average 65 mph takes 6.46 hours — about 6 hours 28 minutes. Add 15–30% buffer for fuel and rest stops on long drives.

Averaging two speeds is not the same as averaging two legs. Drive 100 miles at 70 mph and 100 miles at 35 mph and the trip takes 1.43 + 2.86 = 4.29 hours over 200 miles — an average of 46.6 mph, not the 52.5 mph you get by averaging the two speeds. When legs differ sharply, run each one separately and add the times.

For flights, use scheduled block time instead of cruise speed. A 2,500-mile route at 500 mph cruise looks like 5 hours, but block time also covers taxi, climb, descent, and holding — usually 30–50 minutes more. Divide the distance by the block time in your itinerary to get the average ground speed to enter here.

Multi-day drives are limited by driver endurance rather than distance. Many drivers plan 500–600 miles per day with breaks, and US commercial drivers are capped at 11 driving hours within a 14-hour window under FMCSA hours-of-service rules. Split a long total into daily legs before booking hotels.

The metric switch converts distance and speed together, so the answer does not change: 420 miles at 65 mph and 676 km at 105 km/h both return about 6 hours 28 minutes.

Mountain passes, ferry crossings, and construction detours can add hours beyond straight-line distance divided by speed — build a 15–20% buffer for unfamiliar routes.

Average speed should reflect legal limits and realistic traffic — using the speed limit alone overestimates pace on urban legs.

Night driving and weather reduce safe average speed — lower your input when planning winter or heavy-rain legs.