You already know that a fixed-gear bike has only one gear. Well, it may seem like a dumb question, but if aย fixed gear (or single speed)ย bike has just one gear, then which gear is it exactly? Andย what are the gear ratio and gear inches in the first place?
A bikeโs gear ratio is the number of teeth on the front sprocket relative to the back sprocket. The number of teeth on the front sprocket determines how fast the bike will go, and the number of teeth on the rear sprocket determines how slow the bike will go. A high gear ratio will make the bike go faster, and a low gear ratio will make it go slower. Most fixed-gear bikes come standard with a chainring and sprocket of 46 teeth and 16 teeth, respectively, providing a gear ratio of 46:16.ย
But thereโs a lot more to it than that. So, in this article, you will learn what a gear ratio is, what gear inches are, and how to calculate the perfect gearing for you and your bike. But before we dive too deep into bicycle terminology and its specifics, we need to understand what a gear ratio is.
Editorโs note: This article was updated onย June 13, 2022, to include additional information regarding bicycle gearing.
Before getting to know about gear ratios, letโs first understand their functions in the first place.
What is gear ratio on a bicycle?
A bikeโs gear ratio is the number of teeth on the front sprocket relative to the back sprocket. It also indicates how โeasyโ or โhardโ its gearing configuration is. High gear ratios require more pedal power. Conversely, lower ratios are easier to ride.
You donโt need to calculate the gearโs circumference or anything like that. Just look at the sprockets.
The gear ratio is calculated by dividing two whole integers by the fractional part: the number of teeth on the chainring (the front cog) divided by the number of teeth on the sprocket (the rear gear) (the rear cog).
The gear ratio of a bike with a 46-tooth chainring and a 16-tooth sprocket is commonly denoted with a colon; 46:16.
Gear ratio in decimal form
The gear ratio ofย 46:16, for example, may be represented as 2.875ย when expressed as a decimal. (Youโll get 2.875 if you divide 46 by 16 on your calculator). This implies that, with this 46:16 gear ratio, the rear wheel does over three (2.875) complete spins with each revolution or rotation of the cranks.
What are gear inches?
Using gear inches is aย more accurate way to gauge a bicycleโs mechanical advantage. This measurement takes the diameter of the rear wheel (as well as the width of the tire) into consideration.ย
However, since the 700c rim diameter is common on almost all adult bicycles, and tire width is a very insignificant increase, we may disregard this element and discuss gear ratios exclusively.

Gear ratio on fixed gear bikes vs. geared bikes
Now that weโve learned how to speak about gear ratios, letโs look at an example.ย
Imagine we have a multi-speed road bike with 42 and 52 tooth chainrings and a cassette with 11โ28 tooth sprockets. The sprocket in the fourth slot of this cassette typically has 18 teeth. So the ratio would be 52:18, or 2.88, if you rode this bike โin fourth gearโ with the chain over the large ring.
This is a near approximation of ourย most frequent fixed gearing ratio, which is 46:16. Written as a decimal, thatโs 2.875.
So, to get a feel of what itโs like to ride a 46:16 single-speed bike, you could just change your road bike onto the bigger chainring and fourth sprocket. That is, assuming your gearing configuration follows our example above.
But what if your gearing arrangement differs? In the following part, weโll discover how to figure out what gear on your multi-speed bike best fits the gear ratio of any single-speed bike you would consider purchasing. On a similar note, the torque provides a frictional force that propels the bike forward.
How to choose the right gearing
Now weโre going deep into the weeds of gear ratios. Fortunately, the chart below makes it straightforward to discover equal gear ratios. This way, you donโt even need to make any calculations.
Theย top numbers indicate how many teeth the chain ring has, while the bottom numbers in the leftmost column indicate how many teeth the sprocket has. Dividing the former by the latter gets you the decimal value in the table.
Teeth | 40 | 42 | 44 | 46 | 48 | 50 | 52 | 54 |
11 | 3.6 | 3.8 | 4.0 | 4.2 | 4.4 | 4.5 | 4.7 | 4.9 |
12 | 3.3 | 3.5 | 3.7 | 3.8 | 4.0 | 4.2 | 4.3 | 4.5 |
13 | 3.1 | 3.2 | 3.4 | 3.5 | 3.7 | 3.8 | 4.0 | 4.2 |
14 | 2.9 | 3.0 | 3.1 | 3.3 | 3.4 | 3.6 | 3.7 | 3.9 |
16 | 2.5 | 2.6 | 2.8 | 2.9 | 3.0 | 3.1 | 3.3 | 3.4 |
18 | 2.2 | 2.3 | 2.4 | 2.6 | 2.7 | 2.8 | 2.9 | 3.0 |
21 | 1.9 | 2.0 | 2.1 | 2.2 | 2.3 | 2.4 | 2.5 | 2.6 |
25 | 1.6 | 1.7 | 1.8 | 1.8 | 1.9 | 2.0 | 2.1 | 2.2 |
28 | 1.4 | 1.5 | 1.6 | 1.6 | 1.7 | 1.8 | 1.9 | 1.9 |
You can see that 52:18 was equal to 46:16. You may check this by looking at the drrata in the table above. For example, note that the numbers have been adjusted to 1 decimal point, so 46/16 = 2.875 becomes 2.9.
Letโs assume youโre seeking to purchase a fixie that comes with a 46:18 gear ratio (meaning a 46-tooth chain and an 18-tooth sprocket). What gear on your multi-speed bike might you attempt to get close to the comparable result?
Well, if you look up 46:18 on the chart, youโll see 2.6. So if you see 2.6 anywhere else on the chart, you may assume that the gear ratio is the same.
For example, 54:21 has a value of 2.6, implying you might try pairing your 54-tooth chain ring with your 21-tooth sprocket. Values like 2.5 and 2.7 are similar, so anything like 52:21 or 40:16 would be nearly equal.
Are you looking for more advice? Take a look at this video called โWhat Is The Best Fixed Gear Ratio?โย from the Dave Noakes YouTube Channel.
How can I change the gear ratio on my bike?
A fixed-gear bike with an average 46:16 gear ratio could be what youโre looking for. You enjoy riding it, but you just wish the gearing was a bit easierโthat way,ย climbing hills wouldnโt be such a headache.
The most likely course of action is to upgrade from a 16-to-18-tooth sprocket. The gear ratio would drop from 2.9 to 2.6 due to this change. You can verify this information by looking up the relevant values in the table.
The 46-tooth chainring may be replaced with a 44-tooth one to reduce the gear ratio further. This would have a less significant impact, reducing the ratio to 2.8. However, unlike sprockets, chainrings are often more costly and time-consuming to install.
Of course, if the contrary is true and you want a tougher gear ratioโit may be because your local region is relatively flatโthen youโd either swap to a smaller sprocket or a bigger chain ring.
If you are looking for a rear-wheel cog with a different ratio, check out the ones below.
Frequently asked questions (FAQ)
Below are some commonly asked questions regarding gearing on a fixie, single-speed, or track bike.
What does gear ratio mean on a bike?
Simply put, a bikeโs gear ratio is the number of times the rear wheel rotates for each round of the crank arms (pedals).
What is a good gear ratio for a bike? ย
Most individuals like a ratio of 2.6 to 3.0 in flat areas. The lower end of this range, with a cadence of 90 rpm, will let us travel at roughly 30 km/h, while the higher end will allow us to go at around 34 km/h. A gear ratio of approximately 2.7-2.8 will be appropriate if youโre new to fixed-gear and single-speed bikes.
Is 46:17 a good gear ratio?
Unless you have extremely powerful legs, thatโs a relatively high gear ratio for regular-purpose riding. You may want something a bit lower if youโre starting and stopping a lot like you would in town.
What is a 1-to-1 gear ratio bike?
A 1-to-1 ratio means the sprockets on the chainring and the rear cog will have equal teeth. hens on a one-to-one basis (1:1).
Conclusion
So thatโs it, Gear ratio demystified. And the handy chart makes it even easier to understand!
This article covered what gear ratio is, what gear inches are, and how to calculate the perfect gearing for your bike. Here are some key takeaways:
Key takeaways
- Most fixed-gear bikes come standard with a chainring and sprocket of 46 and 16 teeth.
- Gear inches are more accurate than gear ratios, but theyโre less often used.
- You can change your gear ratio by swapping your bicycleโs rear cog or chainring.
So, what gear ratio configuration are you using? Let us know in the comments below (we read and reply to every comment). If you found this article helpful, check out our full blog for more tips and tricks on everything fixie. Thanks for reading, and stay fixed.
So, have you found a suitable gear ratio? Let me know, I read and reply to all comments.