How to size a baseball bat
Measure height in inches without shoes and weigh the player. Find the height column and the weight row on the chart: where they cross is the recommended length. The calculator rounds to the nearest inch and pound, then reads the same chart.
Age is a rougher guide because kids the same age can be very different sizes. Use it as a cross-check. When height and weight point one way and age points another, go with height and weight.
Length is not the whole fit
The chart sets length only. Weight is a feel question: the drop (length minus weight in ounces) tells you how light a bat swings, and younger hitters usually need a bigger drop to control the barrel. Leagues also decide which bat stamps are legal, such as USA Baseball, USSSA, or BBCOR in high school. Check the league rules before buying.
A common in-hand test: the player should be able to hold the bat straight out to the side by the handle for a few seconds without the barrel dropping. If it dips, the bat is too heavy.
Questions
What size bat for a 10 year old?
By age, 28 to 29 inches. By height and weight it depends on the player: a 54 inch, 75 pound 10 year old reads 30 inches on the Rawlings chart. Enter the player's own numbers above.
What if the chart has a blank for my height and weight?
Rawlings leaves some combinations blank. Add the player's age and the calculator falls back to the by-age range.
Does this work for softball bats?
It gives a reasonable starting length, but fastpitch and slowpitch bats have their own drops and league rules. Check the league before you buy.
Is my data stored?
No. The math runs in your browser and nothing you type is sent anywhere or put in analytics.
Sources
Formulas and rules checked against these sources on October 28, 2026. Leagues and associations change their rules, so when your league's rulebook differs, follow your league.