In short: Distance divided by speed gives a fantasy number that ignores gas stops, food, and the child who needs a bathroom every 90 minutes. This calculator adds break time and an optional departure time so the arrival estimate survives contact with reality.
Updated August 28, 2026, after a fresh review, with updated visuals and links.
Planning a trip that arrives when it says
Core math: 300 km at an honest 100 km/h average is 3 hours; add a 30-minute break and it is 3:30. Choose km or miles; the time math does not care.
Add your departure time and the tool computes clock arrival, flagging trips that roll past midnight. Leaving at 17:30 on a 4-hour trip means arriving around 21:30 with stops, which changes whether dinner is at home or at a drive-through.
The 10-15% realism buffer is not pessimism; it is the difference between highway speed and door-to-door average speed once city traffic, tolls and lights get included. For 300 km that buffer adds about 25 minutes to your estimate.
Worth remembering
- Plan a 15-minute stop every 2 hours of driving; fatigue crashes cluster after long unbroken stretches.
- For trips over six hours, compare against splitting with an overnight stay. A tired second half is slower and far less safe.
Frequently asked
What average speed should I use?
Interstate highway door-to-door: 90-100 km/h in light traffic. Mixed roads: 70-80. City routes: 30-50. When in doubt, use your last trip's average from the car's trip computer.
Why does actual arrival always run late vs GPS predictions?
GPS recalculates with live traffic but still assumes no stops. Every gas, food or bathroom break is pure addition on top, which is why this tool makes breaks an explicit input.
Find every related tool in our Online Calculators: Every Free Tool index.
