Fishing Reel Backing Calculator and Line Capacity Tool
Calculate how much backing and main line fits on your fishing reel, or use Capacity Mode to estimate how much of one line your spool will hold.
Calculate mono backing for braid, fluorocarbon, or other main line
Estimate total reel capacity when you do not want to use backing
Use actual line diameter for more accurate spool-fill results
Save money by using only the amount of premium line you need
Not Sure What Line to Put on Your Reel?
Start with the ReelCalc Setup Wizard. Choose your reel, choose your line, and estimate how much braid, mono, fluorocarbon, or backing fits on your spool.
ReelCalc helps anglers build better fishing line setups by combining reel capacity, line diameter, backing, and working line length. The calculator is prefilled with an example setup so you can see how the results work, then you can replace the numbers with your own reel capacity and line choices.
Fishing Reel Backing + Line Capacity Calculator
Reel Specs
Premium Line
Backing
Measure Your Line While Spooling
A fishing line counter can help you measure how much line is actually going onto your reel, which is useful when adding a specific amount of braid or dividing a bulk spool between multiple reels.
Affiliate disclosure: ReelCalc may earn a commission from qualifying purchases made through this link, at no additional cost to you.
Don’t have your reel nearby? Check out the example values in the calculator above
Using Japanese PE line ratings? Try the PE Line Capacity Calculator to estimate PE braid capacity, backing, and total reel fill using PE sizes, meters, yards, and backing diameter.
Already Know Your Line?
If you already know what line you want to use and just need the diameter, search the ReelCalc Line Database to find the exact line size before using the calculator.
Enter reel specs
Capacity & LB test of line
Enter line diameters
Good line and backing diameter
Save money
No guesswork