Fishing Reel Line Capacity and Backing Calculator
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.
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
Calculate how much braid, mono, or fluorocarbon fits on your fishing reel. Use Capacity Mode for a full-spool estimate or Backing Mode to calculate backing and main-line amounts.
Use the calculator below to estimate backing, main line, or full spool capacity using your reel specs and line 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.
See ReelCalc Tested on Real Reels
See documented spool-ups that compare ReelCalc estimates with the amount of line installed on the reel.
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.
Enter reel specs
Capacity & LB test of line
Enter line diameters
Good line and backing diameter
Save money
No guesswork