How to Measure Handlebar Width (and Choose the Right Size)

Handlebar width has no single measuring rule, so start by checking where your bar’s maker takes the number. On a flat bar, lay a tape across the whole bar from end to end. On a drop bar, measure center to center, once at the hoods and once at the bottom of the drops, because brands label bars by one or the other. To pick a new width, start from your shoulder width and adjust for the riding you do.

How to measure the bar you have

What you are measuring	Where the tape goes	Write down
Flat bar (mountain, hybrid)	Across the whole bar, from one end to the other	Total width, plus the length of each grip if you plan to trim
Drop bar at the hoods	Center of the tube on one side to center of the tube on the other, level with the brake lever clamps	Width at the hoods
Drop bar at the drops	Center of the tube at the lowest point of each drop	Width at the drops. Half the difference from the hoods is the flare per side
Stem clamp area	Metric caliper on the bar where the stem grips it	Diameter in millimeters

Find your starting width

Shoulder width is the usual starting point. Canyon’s rule of thumb is that handlebar width should match your shoulder width. ENVE is more specific: it suggests using your shoulder blade width, measured at the acromion, the very top point of the shoulder bone, then sizing up or down from there for comfort and purpose. Have a friend measure between those two bony points with a soft tape.

From that number, ENVE’s guidance is to go narrower for road racing aerodynamics and wider for gravel, where a wider stance gives more control on rough terrain. Canyon says the same about gravel: wider bars add control on descents, and flared drops help on rough trails.

Flat bars: the push-up method

Park Tool’s method for flat bars, from its guide to cutting bike handlebars, works like this:

1. Get into a push-up position with your hands on the ground, shoulder-width apart.
2. Have someone measure from the outside of one hand to the outside of the other.
3. Add 20 mm for a comfortable margin. That total is the ideal width of the handlebar.

The calculator below does the arithmetic and tells you how much to take off each side if you want to trim a bar that is too wide. Park Tool advises being conservative, because you can always remove more later but you cannot add it back. Only cut a bar if its maker allows it.

Drop bars: the label may not mean what you think

Two bars labeled "40 cm" can differ by several centimeters where your hands actually sit. ENVE's own range shows why. Its standard road bar and its gravel bar are labeled by the width at the hoods. Its aero road bar is labeled by the width at the very bottom of the drops, so a 40 cm bar is only 35 cm at the hoods.

ENVE bar	Label is measured at	Flare per side	Example
Road (compact and standard)	Hoods	1 cm	40 = 40 hoods, 42 drops
SES AR (all-road)	Hoods	2.35 cm	40 = 40 hoods, 45 drops
SES Aero Road	Bottom of the drops	2.5 cm	40 = 35 hoods, 40 drops
G Series Gravel	Hoods	6 cm	42 = 42 hoods, 54 drops

Source: ENVE, how to pick the right road handlebar. Other brands set their own convention, so read the spec sheet of the exact bar you are buying. The finder below converts between the two numbers once you know the flare.

Check the clamp diameter before you buy

Width is the easy part. The bar also has to match the stem's clamp diameter. Park Tool says the most common road bar sizes are 25.4, 26.0, 26.4, 31.8 and 35 mm, that the bar and stem clamp diameters must match, and that you should measure the bar right where the stem will clamp, using a metric caliper. The stem's clamp size is usually engraved or labeled on it. If it is not, ask the stem's maker. Our handlebar clamp diameter chart lists every size with a tool that checks whether a stem will fit.

Tighten the new bar to the torque printed on the stem. If you need a starting reference, the stem bolt torque chart explains how to find it. A bar that turns or slips under braking usually points to a clamp problem, covered in why handlebars slip in the stem.

When the bar is not the problem

Sore hands or a stretched-out feeling can come from reach and height rather than width. Stem length, bar height and frame size all change the same contact points. The common bike fit problems guide shows how to tell them apart, raising the handlebars covers the height side, and flat bar vs drop bar helps if you are deciding between bar types altogether.