Fishing Reel Line Capacity Calculator
Calculate line capacity for different fishing line diameters and lengths on your reel spool
Calculate Reel Line Capacity
Published Line Parameters
Find these values on your reel, spool, or packaging (e.g., "0.23mm-200m" or "0.23/200")
New Line Parameters
Enter the diameter of the new line you want to use
Calculation Results
Formula used: diameter² × length = spool capacity
Calculation: 0.00² mm × 0.0 m = 0.00 mm²⋅m
Example Calculation
Spinning Reel Example
Published specs: 0.25mm / 150m
Spool capacity: (0.25)² × 150 = 9.375 mm²⋅m
New line: 0.30mm diameter
New capacity: 9.375 ÷ (0.30)² = 104.2m
Baitcast Reel Example
Published specs: 12 lb test / 120 yards
Conversion: ~0.28mm diameter, ~110m length
Spool capacity: (0.28)² × 110 = 8.62 mm²⋅m
For 15 lb test (~0.32mm): 8.62 ÷ (0.32)² = 84.2m
Fishing Line Types
Monofilament
Most elastic, sensitive to UV light
Braided
Strong for diameter, no stretch
Fluorocarbon
Invisible underwater, sinks fast
Wire
For toothy fish, trolling
Fishing Tips
Don't overfill your spool - leave 1/8" from rim
Use backing line to fill spool economically
Thicker line reduces capacity but increases strength
Braided line allows more capacity than mono
Check line capacity before buying new line
Consider line memory and stretch for your fishing style
Understanding Fishing Reel Line Capacity
What is Line Capacity?
Line capacity is the maximum amount of fishing line your reel spool can hold. It's determined by the spool's volume and the diameter of the line being used.
The Calculation Formula
diameter² × length = spool capacity
This formula is based on the cylinder volume principle, where the cross-sectional area (proportional to diameter²) multiplied by length gives the volume of line on the spool.
Why Line Diameter Matters
- •Thicker lines take up more spool space
- •Diameter affects casting distance and line visibility
- •Different line types have different diameter-to-strength ratios
- •Braided lines offer more capacity than monofilament
Practical Applications
Use this calculator when switching line types, upgrading to different test strengths, or optimizing your reel setup for specific fishing conditions and target species.