### Old-Fashioned GPS

I’m sure there are math people out there in the crowd who can do all sorts of complex calculations in their heads, but for the rest of us, here’s a simple way to estimate the time it will take to travel a distance without using a cyclometer or GPS.

- If your average speed is 10mph, multiple your trip distance (in miles) by 6 to get the number of minutes it will take to cover the distance.
- If your average speed is 12mph, multiple your trip distance (in miles) by 5 to get the number of minutes it will take to cover the distance.
- If your average speed is 15mph, multiple your trip distance (in miles) by 4 to get the number of minutes it will take to cover the distance.
- If your average speed is 20mph, multiple your trip distance (in miles) by 3 to get the number of minutes it will take to cover the distance.

## 15 Responses to “Old-Fashioned GPS”

Good ol’ division…

Oooh, you forgot 17 mph, multiply by 3.5 and 24 mph multiply by 2.5. Of course, if you are in a wicked fast paceline, you could do multiply by 2 for 30 mph.

“Oooh, you forgot 17 mph, multiply by 3.5″Actually, it’s 3.529, but who’s counting? ;-))

Alan

PS – I’d like to see 24mph on a Ma or Pa… :)

and if you’re “breaking away,” drafting a semi, you don’t need any math!

… if your average speed is 20mph, don’t bother, you’ll be there shortly anyway :-)

Having been out all day I was lucky to see a (rolling) average of just over 12mph. But there were lots of hills and rough roads and…

This looks handy, but might be even more useful with a few pointers on how to figure out your average speed without using a cyclometer or GPS. I guess if you use a map to figure out the distance of your route, and if it’s a route you travel frequently (such as a commute) you can figure out how long it takes to get from point A to point B and thus come up with an average speed. But if you’re doing a one-time trip, such as a cycling tour, I’m not sure how you’d estimate your average speed easily without a gizmo to help you.

@Brad

If you do this frequently enough you’ll pretty quickly get an idea of your typical average speed. I’d guess most commuters and utility bicyclists ride the same routes fairly often…

That’s fantastic. The speeds increase by a fifth, a quarter, a third and a half. And if you keep going, by 100%, by 200%, and so on. Unfortunately, the increase in time savings drops off as quickly as the speed increases.

This is amazing. As long as you use minutes to measure travel time, it’s a mathematical impossibility to devise a form of transportation more efficient than the bicycle. :-)

I’d call this Old fasioned ETA more so than GPS…

Hey, that’s tricky! Let me add the International Units version:

15km/h: 4 minutes per km

20km/h: 3 minutes per km

30km/h: 2 minutes per km (wow, that’s fast!)

For the more avid ones (I personally like to hurry when possible) in city traffic a good choice would be half an hour for each ten km (main streets only), plus a time to cool down!

@Erik

once in my life (during a vacation trip) I got used to measure my travel time in DAYS… Wish it will be possible to do it again… (later I realized that the car/bike travelling time conversion is 1hour/1day… Even so, some car trips seem soooo long and boring…)

@ Helton

The real trick is to figure out in your head how long it will take to reach your destination in miles while traveling in km/h ;)

I like this. I took my computer off my bike a couple years ago and haven’t looked back. I know my average speeds, and it works like a clock with distances I travel. It was distracting to look at it when I should be enjoying the scenery. It made me too focused on the numbers, which were all too predictable.

I dumped my speedo on my commute bike for the same reasons others have mentioned. Its so easy to find the distance on a map and use your watch along with pencil and paper to figure average speed etc. I had a customer get lost tonight when they forgot their Garmin at home. Back in the day, we used a road map….. no batteries needed and cheap to buy at every gas station. They always have a scale for figuring distance and ones average speed rarely varies. Technology is cool but highly overrated for many things. I’d prefer a high quality lighting set up rather than a glorified electronic map or speedometer. Sorry, I’m just a grumpy old man !

GPS , does this mean I have to stop navigating by the sun ? Speed : slower then the birds , faster then a horse and carriage . LOL

Personally, I prefer to carry an astrolabe.