Commute Time Calculator

Commute time and leave time calculator for arriving on time

This commute time calculator is built for one specific decision: figuring out what time you should leave to arrive by a target time. If you have ever looked at the clock and guessed, then arrived late (or too early), this gives you a repeatable way to plan your departure. It is intentionally simple, so you can use it quickly without needing route apps or perfect traffic data.

The calculator estimates driving time from distance and average speed, then adds optional minutes for expected traffic delay and a safety buffer. The result is a practical total commute time you can plan around, plus a suggested leave time based on your arrival time. For example, if you need to arrive at 08:30 and your total commute is 42 minutes, the suggested leave time is 07:48.

Use it as a planning baseline for recurring commutes: work, school runs, gym, or appointments where being on time matters. It is not trying to be a route planner or replace live navigation. Its job is to translate what you know (distance, typical speed, and a realistic buffer) into a clear leave time you can follow. If you want to be more conservative, increase the buffer. If you usually hit delays on certain days, add traffic delay.

Assumptions and how to use this calculator

• Average speed is your typical overall speed for the whole trip (including slower sections), not your peak speed on open roads.
• If you leave traffic delay blank, the calculator assumes 0 minutes of delay.
• If you leave buffer blank, the calculator assumes a 10 minute buffer to cover parking, walking, and small unknowns.
• The calculator treats the commute as a single continuous trip and does not model stops, refuelling, or multiple legs.
• If the suggested leave time is before midnight (meaning you would need to leave the previous day), the result will clearly say so.

Common questions

What should I enter for “average speed” if I am not sure?

Use a conservative estimate based on your real experience, not the speed limit. If your commute is mostly urban with traffic lights, 30 to 45 km/h is common. If it is mixed suburbs and highway, 45 to 70 km/h is often realistic. If you are unsure, start with 50 km/h and then adjust after a few days by comparing the estimate to your actual arrival.

Why does the calculator use distance and speed instead of asking for my route?

Because the intent here is planning, not navigation. Route-based planning requires live data, maps, and constant updates. Distance plus typical average speed is enough for a stable baseline you can reuse every day. If live traffic changes your trip, add a traffic delay estimate or increase your buffer.

What is the difference between “traffic delay” and “buffer”?

Traffic delay is extra time you expect on the road (slowdowns, congestion, known choke points). Buffer is off-road and uncertainty time (parking, walking, elevators, security, finding the right office). If you are always late by a few minutes even when driving time is accurate, your buffer is too small.

Does this work for public transport commutes?

Not reliably. This page is locked to driving commutes where time is mainly determined by distance and average speed. Public transport depends on schedules, transfers, and waiting time, which this calculator does not model. If you still want a rough baseline, you can approximate by using total route distance and an effective speed, but expect wider error.

How do I make the estimate more accurate without making it complicated?

Track your last five commutes and note the actual minutes door-to-door. Compare that to the calculator’s total commute time. If the estimate is consistently low or high, adjust your average speed and keep the same buffer. If the variance is wide, keep average speed realistic and increase buffer to cover the worst common outcome.