Imperial or Metric and Racing

I am an American cyclist. I train my TT and Road Races (I know what’s that? :-)) with imperial measurements. As I prepare for 2023 racing I have been thinking I should go with metric. I will be in Italy in June for a long event as well.

How long did it take for other folks who use imperial measurement in their daily life to adjust to metric? Did you switch to gauge distance over time in events to match the signs on the road?

Did you train with km before your events?

Love to hear some thoughts.

Not long, I guess, though I still think in imperial units for the most part. Also I just ballpark the conversions. If I had a specific race in mind I’d probably convert it exactly.

km ~= miles * 1.5
miles ~= km * 0.6
Deg F ~= Deg C * 2 + 30

None of those are exactly right but I can do them in my head and they’re close enough for the distances/temperatures I care about.

As an engineer I really wish imperial units would die a fiery death.


Love it. A fiery death! I might do metric on my head unit and have Strava stay imperial.


The only thing I know is that I am faster in KM and lighter in KG….but always colder in C.



If you use a Garmin, consider using the Connect IQ datafield Distance in Opposite Units.

This can be especially useful if you want to keep using mph for speed as it is what you are familiar with, but want to use km for distance on the event day so that it matches the course markers.

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Nuff said…

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Living in the UK I use both… :rofl: I find my brain just switches as necessary. I’m sure it wouldnt be too hard to adjust :slight_smile:

Driving: miles
cycling: km
Person height: feet/inches
building height: metres
weight: kg
fishing: lbs



Also UK and totally agree… I’d also add running -KM and for body weight I’m happy using stones and lbs, just lbs (US style) or KM!

Never understood why I run in KM and mins/KM but cycle in miles and mph!


I’m also in UK. My GPS has been on km since 2010 when I started riding audax events. Also noticed my car sat nav was in km the other day, haven’t driven on the Continent since I drove to the Dolomites in 2018 pre pandemic. Shows how much the units make a different (not).

Like others I’ll convert between miles and km with rough numbers

10km = 6 miles
10 miles = 16 km
24km = 15 miles

But most often I don’t bother converting as I’m rarely focused on distance during a ride.

I once had a young apprentice who gave me measurements in a mixture of both.

“It’s needs to be 26 inch and 4mm”


Also in UK. I use km exclusively for cycling and running (infact all outdoor activities - for hiking etc our OS maps are in km anyway). Driving I use miles and mph just because of speed limits and road signage, between that and ordering beer it’s the only imperial I regularly use.

I convert really easily in my head - it’s 5:8 km:miles, and 10 miles is obviously 16km (16.1 to be precise) so 20 mph is ~32kph etc, which doesn’t take a lot of thought really. I rarely need to convert on the bike though as I usually either have a route on my Garmin (so road signs for distances are pretty irrelevant) or I already know where I am going…

Road signs can be pretty inconsistent, you might see a sign that says “[Town] 8 miles” twice, nearly a mile apart… So they are not much use for micro-navigation. Also the distance by the signed route is regularly not the same as the route I am taking, as the signs are obviously intended for cars so they will take you down roads that I would rather avoid. So the fact road signs are in miles doesn’t really matter on the bike (and the approximate conversion isn’t hard anyway).

I use ml and grams for cooking and so on… But I can tell you off the top of my head that a pound is 454g and a UK fluid ounce is just over 28ml for example… And there’s 568ml in a UK pint, 284 in a half etc etc…

I am pretty good at converting from stone and pounds to kg as I track my weight in kg (watts per kilo!) but my wife keeps the bathroom scales in stone and pounds!


Hahaha. Yep!!!

You’re showing off. :rofl:

There are 2.20462 pounds in a kg, remembered from child hood , when a group of us tried to memorise them.

So much fun hearing from all of you. Thanks a million for the laughs too! It’s cold here and I needed to not be so grumpy about not getting any outside time.

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Hahahaha!!! Love it!!!

I’m in the UK and I think I mostly use imperial (miles, mph, feet and inches, stones and lbs) simply as thats what I am used to. Except temperature where I use Celcius as thats what I am used to there. For anything technical though I use metric as the maths is easier.

Why people or few countries still use imperial???

When website shows imperial by default, i facepalm.

There are two types of countries in the world…those who have put a man on the moon and those that use the metric system.