700c Equals How Many Inches (Easy Answer)

If you’ve got a bike with 700c wheels and are trying to find tires and inner tubes to fit them, then you’ve come to the right place.

It can be a bit of a minefield determining the correct size tubes and tires for bikes and it’s made 10x harder when manufacturers swap between imperial and metric figures. The simple answer is that 700c equals 27.5 inches but, unfortunately, it’s not as simple as that. Buy a 27.5 inch tire and inner tube for your bike and they’ll likely not fit.

But don’t worry, I’ve got your back. I’ve got recommendations below for tires and tubes to fit all types of 700c wheels. I’ll then give you a quick summary of how to find your tire size (because it’s not just “700c”), and we’ll also look at what the numbers mean and why it’s not as easy as swapping from millimeters to inches and back again. I’ll go into some extra details on how to choose a great set of tires and tubes for 700c wheels and, finally, I’ve got a quick refresher on changing tires and tubes.

Let’s dive in.


How to determine your 700c tire size and what the numbers mean

Half the battle with tracking down replacement parts for bikes is trying to work out what the ‘code number’ or make/model/SKU of a particular item is. Thankfully, when it comes to tires and tubes, the manufacturers usually make this a very easy process.

Squat down to one side of your bike and take a look at the sidewall of your tire. This is the rubber circle that sits in between the metal tire rim and the rubber tread (the bit which makes contact with the ground). On some bikes, such as hybrids, cruisers and BMXs, the sidewall can be a different color, on other tires it’s generally standard black rubber.

Next, look along the sidewall and you should see a number of words, letters, and numbers either printed or embossed in the rubber surface. You might see a brand name, such as Michelin or Continental. You should also see the “700c” along with some other numbers. It will likely look like the following:

700c x 38

This will be the size of your tire and is all the information you’ll need to choose a new tire and inner tube. This is what the letters and numbers of this code mean:

“700” is the nominal diameter of the tire in millimeters.

“c” refers to a (now obsolete) French system of classifying tire widths. It ran from ‘a’ to ‘d’ with ‘a’ being the narrowest up to ‘d’, the widest.

“x” means multiplied by.

“38” is the nominal tire width.

When you’ve found the equivalent size on your own bike tires, compare it to the table above and you’ll see which tires and tubes I recommend for your bike. Simple!

Trying to convert from millimeters to inches, and pairing an “inches” tire with a “millimeters” bike wheel is likely to cause problems. Either the tire will be too big for the wheel and you won’t be able to fit it. Or, it will be too small, and you won’t be able to fit it either. Far easier to choose a “millimeters” tire for a “millimeters” bike wheel.


Choosing a 700c bike tire that fits

Once you’ve found your sizing code, you can go right ahead and choose the correct tire using the table above. If, for example, your tire size is “700c x 38” then scroll down the table until you find that size and then look to the left for the appropriate tire recommendation.

For the slimmer tires shown in the table (e.g. 700c x 23 to 700c x 28) I’ve recommended tires with a smoother and less pronounced tread pattern. Bikes with narrow tires, like these, are usually most used on roads and other smooth pavement surfaces. They’re designed so that you can go faster and are often found on bikes such as hybrids, cruisers and road bikes.

Wider tired bikes (700c x 30 and upwards) tend to be used on much more varied surfaces. These might include smooth pavement but are also likely to include off-road trails and tracks, some with gravel or looser sandy terrain. For these, you need tires that have more grip so that you don’t slip and still have the traction you need to corner safely and go up hills. The tires that I recommend for these wheels therefore have more knobbly grips on them.

These tires get excellent reviews from users for performance and durability.


Choosing an inner tube for a 700c bike tire

Inner tubes are a little easier to pick as they’re a little more forgiving than tires. Tubes are a little like those magician’s modelling balloons. They blow them up, then twist them into various shapes, and out pops a cute model dog for a birthday boy or girl. The key aspect here is that the width of the balloon varies according to how much air the magician blows into it. Same for inner tubes.

This means that any given size of inner tube can be used with a range of tire sizes. Inflated a little more for larger tire widths, inflated a little less for smaller tire widths. Bear in mind that the overall diameter of the tube won’t change, no matter how much air you blow into it.

So, how to choose the correct size of inner tube for your bike wheel? First, find your tire size by looking along the side wall for the tire code. Let’s say that this is “700c x 38”. You now need a tube that is 700 diameter, with a width range that includes 38. A bike tube that is “700c x 35-40” would therefore be perfect.

I like to make things even easier, so all you have to do is take your bike tire code (e.g. “700c x 38”) and look down the table above until you find that code in the left column. Look across to the right until you see the button that says “View tube”. Click. Buy. Fit. Go out and ride your bike with a grin on your face.


How to change a bike tire and tube

And how do you fit a replacement tire and tube? If you’ve never done this before (or you’re a little rusty!) then don’t worry. It’s an easy process, though can be a little fiddly to begin with.

You will need the following:

  • Replacement tire or tube (or both) as necessary
  • Set of tire levers (plastic ones are great as they are very light)
  • Bike pump

It will take around 30-40mins to change a tire and tube and there are a number of steps to this:

  1. Undo the quick release bolt at the wheel hub and remove the wheel
  2. Deflate the tire, if needed
  3. Remove the old tire using the tire levers to prise over the wheel rim
  4. Remove the old tube
  5. Check for any sharp objects inside the wheel rim
  6. Fit the new tube
  7. Loosely fit the new tire
  8. Partially inflate the tube
  9. Fit the tire inside both wheel rims
  10. Fully inflate the tube (and check it holds its pressure)
  11. Re-fit the bike wheel, checking that the quick-release bolt is tight

There’s a quick YouTube video here which gives a good run-through of this process: