The formulas
Speed = Distance ÷ Time
Distance = Speed × Time
Time = Distance ÷ Speed
Keep units consistent. If speed is in km/h, distance must be in km and time in hours. Thirty minutes is 0.5 hours, not 30.
Handy conversions
| From | To | Multiply by |
|---|---|---|
| km/h | m/s | 0.2778 (or ÷ 3.6) |
| m/s | km/h | 3.6 |
| km/h | mph | 0.6214 |
| mph | km/h | 1.609 |
Worked example
Driving 320 km at an average of 60 km/h:
| Step | Working |
|---|---|
| Time | 320 ÷ 60 = 5.33 hours |
| In hours and minutes | 5 hours 20 minutes |
| Plus two 20-min breaks | ≈ 6 hours total |
Average speed is not cruising speed. Traffic, toll plazas, town stretches and breaks all pull the average down — on Indian highways, planning at 55–65 km/h average is usually more realistic than the 80–100 km/h you see on the speedometer.
Typical journey times
| Distance | At 40 km/h | At 60 km/h | At 80 km/h |
|---|---|---|---|
| 50 km | 1h 15m | 50m | 38m |
| 100 km | 2h 30m | 1h 40m | 1h 15m |
| 250 km | 6h 15m | 4h 10m | 3h 8m |
| 500 km | 12h 30m | 8h 20m | 6h 15m |
| 1,000 km | 25h | 16h 40m | 12h 30m |
Average speed is not the average of speeds
Travel 100 km at 100 km/h and return at 50 km/h. The average is not 75 km/h.
The outward leg takes 1 hour, the return takes 2 hours. Total: 200 km in 3 hours, so the average speed is 66.7 km/h. You spend more time at the slower speed, so it weighs more heavily.
Average speed is always total distance divided by total time, never the arithmetic mean of the individual speeds.
Common mistakes
- Entering 30 for half an hour instead of 0.5.
- Mixing km with mph.
- Averaging two speeds directly.
- Planning a road trip at cruising speed rather than realistic average speed.
- Forgetting breaks, fuel stops and meals on long drives.
Working out fuel for the same trip? Use the fuel cost calculator.
Frequently Asked Questions
How do I calculate travel time?
Divide distance by speed. 320 km at 60 km/h takes 5.33 hours, which is 5 hours and 20 minutes.
How do I convert km/h to m/s?
Divide by 3.6, or multiply by 0.2778. So 72 km/h is 20 m/s.
Why can't I average two speeds directly?
Because you spend more time travelling at the slower speed, so it carries more weight. Always divide total distance by total time.
What average speed should I plan for on Indian highways?
Usually 55–65 km/h including traffic, toll plazas and town stretches, even where the speed limit is much higher.
How do I convert km/h to mph?
Multiply by 0.6214. So 100 km/h is about 62 mph.
Should I add time for breaks?
Yes. On long drives, allow roughly 20 minutes every two to three hours, plus meal stops. It adds up quickly on a full-day journey.
Kuch aam Indian routes
Approximate driving time, realistic average speed par:
| Route | Doori | Samay (stops ke saath) |
|---|---|---|
| Delhi → Jaipur | 280 km | 5–6 ghante |
| Mumbai → Pune | 150 km | 3–4 ghante |
| Bengaluru → Mysuru | 145 km | 3 ghante |
| Chennai → Pondicherry | 160 km | 3–3.5 ghante |
| Delhi → Agra | 230 km | 3.5–4 ghante (expressway) |
| Ahmedabad → Udaipur | 260 km | 4.5–5 ghante |
Ye figures shehar se nikalne aur ghusne ke traffic ko jodkar hain — sirf highway speed se ginenge to hamesha kam aayega.
Average speed ka ek dhokha
Ek aam galti: agar aap 60 km/h se gaye aur 40 km/h se laute, to average 50 km/h nahi hota.
100 km ek taraf maaniye. Jaane mein 1 ghanta 40 minute, aane mein 2 ghante 30 minute. Kul 200 km, 4 ghante 10 minute mein. Average = 200 ÷ 4.167 = 48 km/h.
Kyunki dheemi raftaar par aap zyada der tak chalte hain, wo average ko apni taraf zyada kheenchti hai. Average speed hamesha kul doori ÷ kul samay hota hai — speeds ka average nahi.
More questions
Road trip ke liye kaunsi average speed maanein?
India mein lambi drive ke liye 50–60 km/h realistic hai, chahe highway par aap 90 chala rahe hon. Traffic, toll aur stops sab isme aa jaate hain.
Kya jaane aur aane ki speeds ka average le sakte hain?
Nahi. Average speed kul doori ko kul samay se divide karke nikalti hai. 60 aur 40 ka average 50 nahi, 48 km/h hota hai.
Related calculators and guides
Disclaimer. This calculator provides estimates for general guidance only and is not financial, tax or legal advice. Rates, rules and limits change, and your own situation may differ. Please verify current figures with the relevant authority or a qualified professional before acting on them.