Bat Swing Weight Calculator
Calculate your bat's true swing weight (MOI - Moment of Inertia) to understand how it will feel during your swing.
Enter Bat Measurements
How to Measure Your Bat
1 Weigh Your Bat
Use a precise scale to measure your bat's total weight in ounces. Kitchen scales work well for this.
2 Find the Balance Point
Balance the bat on your finger or a thin edge. The point where it balances is the balance point. Measure from the knob to this point in inches.
3 Set Up Pendulum Test
Choose a pivot point to hold the bat. Common options:
- At the knob: Easier to hold steady (Distance to top of knob = 0)
- Above the knob: Where your hands normally grip (Distance to top of knob = 1-2 inches)
Measure the distance from your pivot point to the top edge of the knob.
4 Time the Pendulum
Hold the bat horizontally at your pivot point and let it swing freely like a pendulum. Time one complete back-and-forth swing. For accuracy, time 10 swings and divide by 10.
5 Enter Values
Input all measurements into the calculator above to determine your bat's swing weight.
Popular Bat Swing Weights
Understanding Swing Weight
What is MOI?
Moment of Inertia (MOI) measures how difficult it is to swing a bat. Unlike total weight, it accounts for weight distribution. MOI is measured at 6 inches from the knob - approximately where your hands grip the bat.
Typical MOI Ranges (Based on Actual Testing)
BBCOR Bats:
- Light Swing: Under 9,250 oz·in²
Examples: DeMarini Zen (~9,105), Marucci CAT X2 (~9,107) - Balanced: 9,250-9,800 oz·in²
Examples: Louisville Slugger Meta (~9,521), Rawlings ICON (~9,398) - End Loaded: Over 9,800 oz·in²
Examples: Marucci CAT X Connect (~9,905), DeMarini The Goods (~9,657)
USSSA Bats (Drop 10):
- Light Swing: Under 4,950 oz·in²
Examples: Warstic Bonesaber (~4,319), Easton Hype Fire (~4,846) - Balanced: 4,950-5,500 oz·in²
Examples: Louisville Slugger Meta (~5,208), Axe Avenge Pro (~5,247) - End Loaded: Over 5,500 oz·in²
Note: Drop 10s rarely exceed 6,000 oz·in²
USSSA Bats (Drop 5):
- Light Swing: Under 7,500 oz·in²
- Balanced: 7,500-8,000 oz·in²
- End Loaded: Over 8,000 oz·in²
Examples: DeMarini Zen Drop 5 (~8,153), Rawlings ICON Drop 5 (~8,174)
USA Bats:
- Drop 10-11: 5,500-6,500 oz·in²
Most common youth size (31/21) - Drop 5: 7,500-8,500 oz·in²
Transition to BBCOR size (32/27)
Fastpitch Bats:
- Light Swing: Under 7,500 oz·in²
Drop 10 models (33/23) - Balanced: 7,500-9,000 oz·in²
- End Loaded: Over 9,000 oz·in²
Power hitter models
The Physics Behind It
This calculator uses the pendulum method formula: I = (T²×m×g×d)/(4π²), then applies the parallel axis theorem to standardize measurements at the 6-inch reference point where your hands grip the bat.
About the Measurements
Balance Point: Always measured from the knob end to where the bat balances.
Pivot Distance: Measured from your pivot point to the top edge of the knob (where the knob meets the handle). This accounts for the knob's thickness and ensures accurate calculations.