The authors of this article both have bikes and tested the calculators listed below for themselves. The results were consistently accurate and that’s why we chose to recommend these bike size calculators to you. Your bike size will, for obvious reasons, depend on which kind of bike you are looking to buy so we start out with definitions of various bike types. Once you decide on that, you will start taking your measurements and entering the values in the bike size calculators.
#1 Pick the type of bike that best suits your needs
The bike size that best suits your measurements actually depends on the kind of bike you are going for as well. Below, we will give a brief description of various bike types and their physical features.
Mountain bikes
MTBs are designed for off-road riding. They typically come with flat handlebars and wide tires, which absorb bumps better than thinner flats and allow for more balanced rides on uneven terrain. MTBs tend to have smaller frames than road bikes. This makes maneuvering easier, which is crucial when cycling off-road.
Road bikes
Road bikes are designed for roads and smooth surfaces. What physically sets them apart is that they are usually lighter than other bikes. They also typically have narrow tires and bent handlebars.
Gravel bikes
They are similar to road bikes but gravel bikes have certain features that allow for riding on the road as well as off it. These features may include additional clearance for wide tires and disc brakes. Gravel bikes are a great option for bikers who don’t want to commit to a certain kind of terrain.
Hybrid bikes
Hybrid bikes blend physical features of road bikes, mountain bikes and touring bikes to offer a comfortable riding experience that is not so specialized. Similar to mountain bikes, hybrid bikes typically have straight, flat handlebars and assume an upright riding position. But they are typically lighter than mountain bikes and have narrow tires like road bikes.This allows the rider to reach high speeds without having to exert themselves too much. Finally, hybrid bikes have places to mount racks and bags to carry belongings similar to touring bikes. There are various kinds of hybrid bikes such as trekking, cross, commuter, city and comfort. The kind that’s best for you depends on your intended use. However we will touch on city bikes as they are very popular in metropolitan areas.
City bikes
They are also known as utility bikes given their low-maintenance nature. City bikes are designed for moderately-paced, short-to-medium length rides through a variety of weather conditions. They are for bikers who get on the saddle simply to commute in urban areas. Their design tends to focus on convenience and comfort as opposed to speed or the ability to go on uneven terrain. That’s why city bikes usually have bigger saddles and elevated handlebars which allow for an upright sitting position while riding. They are also typically heavier than road bikes.
#2 Take your measurements
Here we list some of the measurements you may need when using a bike size calculator and how to find these measurements. You may not need all of these so you should check which information your preferred calculator needs in order to find your size below (in section 3).
Inseam
What you will need: wall, hardcover book, pencil, measuring tape
Inseam is an inner leg measurement that tells you how high your crotch is from the floor when you are standing straight. The best way to measure it is to place a book inside your thighs, spine of the book facing upwards while standing straight with your back to the wall and your feet 6-8” (15-20 cm) apart. Make sure the placement of the book is as high as possible without causing discomfort. Then take a pencil and mark the highest point where the book makes contact with the wall and measure the distance of the marked point from the floor. This gives you your inseam measurement.
Sternal notch
What you will need: wall, measuring tape
This is basically the height of the V right below where your neck ends between your collarbones. You can use a measuring tape while standing straight against a wall to measure this yourself but getting a friend to do this for you might yield more accurate results. Remember you want to get the distance between the top of the notch and the floor.
Height
What you will need: wall, pencil, measuring tape
Pretty self-explanatory but essential to have if you want to utilize an online calculator to find your bike size. You can use the good old method of marking the wall right above your head while standing straight against the wall and measuring the height of the marked point.
Lower Arm & Upper Arm
What you will need: wall, stool, cylindrical shape, cardboard or flat surface, measuring tape
Best way to measure your lower arm length for our purposes is to extend your forearm in front of you while holding a cylindrical shape in your hand and measuring the distance from the center of the object to your elbow. Make sure the axis of the cylindrical object is perpendicular to the axis of your forearm. Continue to hold the object and extend your arm parallel to the floor. Feel the joint where your shoulder connects to your upper arm and measure from there to the middle of the cylindrical object. Take these measurements for both arms and then take the average.
Upper Leg & Lower Leg
What you will need: wall, stool, cardboard or flat surface, measuring tape
Place a stool right in front of the wall and sit on it with your back right against the wall. Make sure your upper legs are parallel to the floor and lower legs are perpendicular to it. In order to measure the length of your upper legs, first place a cardboard or a flat surface across your knees, perpendicular to the floor. Then measure the distance from the inside of the cardboard to the wall. Once you’re done with that, place the cardboard flat on your kneecaps so it will be parallel to the floor. The height of the cardboard from the floor will give you the length of your lower legs. Find these measurements for both your legs and average them.
Torso
What you will need: wall, stool, cardboard or flat surface, measuring tape.
Place the flat surface across the bony part of your shoulder while still sitting straight on the stool. Measure the distance from the bottom part of the surface to the top of the stool. Do this for both shoulders and take the average.
#3 Find a good bike size calculator
Cyclesimply Bike Size Calculator
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Other Calculators
- https://www.competitivecyclist.com/Store/catalog/fitCalculatorBike.jsp
- Measurements you will need: Inseam, sternal notch, height, lower & upper arm, upper & lower leg, torso length
- For the following bikers and bike types: Men & women/road & mountain bikes
- https://www.omnicalculator.com/sports/bike-size
- Measurements you will need: Height, inseam length
- For the following bikers and bike types: adult & child/ trekking, city, hybrid, road/ gravel, mountain bikes
- https://www.bikeexchange.com/promo/bike-size-calculator
- Measurements you will need: inner leg length (inseam)
- For the following bike types: road, mountain, touring, fitness, city urban bikes
- https://www.bergfreunde.eu/bike-frame-size-calculator/
- Measurements you will need: Inside leg length (inseam)
- For the following bike types: Mountain, road bike & cyclocross, trekking & touring, city & everyday
#4 Post-purchase adjustments
Once you get your bike delivered and start riding, you could still adjust certain things to make it more comfortable for you. If these aren’t adjusted correctly, your rides might feel awkward even if your bike is the correct size for you. So make sure to make your bike fit you by adjusting the following:
- Seat post height (for more on this, check out our post titled: "How to Set Your Set Your Saddle Height")
- The position and size of stem
- Handlebars
- Cranks
- Saddle position
We hope you found this article about finding your correct bike size useful. If you are going to opt for online bike size calculators, we would recommend using as many calculators as possible and comparing the results. In the ideal scenario you will get consistent results across various calculators. If this is not the case for you, there might be additional value to finding your bike size in person with the help of a professional. We also recommend you check out the shopping guides on our website where we go into detail about specific bikes.
Bike Size Calculator:
Cyclesimply Bike Size Calculator
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