Figuring Fishing Reel Line Capacities for Mexico Travel Logo
Figuring Fishing Reel Line Capacities for Mexico Travel


Mexico Travel Fishing Reel Capacity Spreadsheeet Photo

A spreadsheet confirms the simple but useful formula for estimating line capacities on the fishing reels you take to Mexico.


By Gene Kira, September 22, 2003, as published in Western Outdoor News:

After too many seasons of nursing things along with epoxy glue and sewing thread--and knowing just where to apply finger pressure in some cases--quite a bit of my Mexico fishing tackle finally melted, wore out, broke, rusted up, or just fell apart this summer.

Sadly, I look in a drawer of bent rod guides, bent reel parts, and so forth, and admit to myself that most of it is...well...junk.

So now, I'm having fun researching the catalogs and making phone calls, getting ready to wrap a nicely coordinated set of rods, and lay out some serious pesos for a new set of reels.

One of the things I'm trying to do, of course, is design a coordinated outfit that does a decent job in various fishing situations, but still lets me travel light and fast to Mexican sportfishing destinations. I figure that I need four line weights and five rods to get the job done.

I'm also trying to get away with only four reels when traveling and fishing in Mexico, so their line weights and capacities must be very, very carefully integrated, or there will be gaps in the lineup where something--like a sergeant major or a 50-pound dorado, for instance--might sneak through.

But in perusing reel specs, it's often frustrating to check the specified fishing line capacities and realize that they don't cover all the possible weights you might want to wind on. So the question often is, for instance, if this reel holds 400 yards of 40-pound line, how much 25-pound will it hold? Or how about 80-pound, if you want to go in the opposite direction for some special purpose--like Midriff yellowtail, for instance?

Of course, you always figure that line strength is a simple function of cross-section, so if Line A is twice as strong as Line B, it should also take up twice as much space; a reel that holds 1,000 yards of 40-pound, for example, you would expect to hold about 500 yards of 80-pound.

But, how accurate can this simple logic be in the "reel" world?

This basic formula has always seemed too simple to be really trustworthy, and the manufacturers' numbers never seemed to work out correctly--at least according to my eight fingers and two thumbs; I always wondered what other factors should be entered into the formula.

Not believing it could be so easy, for example, I laboriously attempted to calculate such things as the different percentages of space I assumed would be lost to "air," depending on if heavy or light line were used. But all I came up with was gobbledygook that didn't dovetail with the published numbers.

So, recently, in planning my new tackle set-up, I decided to abandon fancy "theory" and rely instead on empirical data. I created a simple spreadsheet and entered 136 different reel line capacities--from 2-pound test to 80-pound test--as loaded on 24 popular conventional and spinning reels, from various manufacturer's spec sheets.

Using the computer's ability to crunch arithmetic and sort the results in endless ways, I checked the simple, basic theory against real numbers, and found that it actually works. It's also remarkably accurate, but only when used properly, and with the proper math. The formula, it turned out, is simple and easy to remember, even though it is far from intuitive (for me, anyway).

Here's how it works:

--Take any reel, for example, one that holds 450 yards of 30-pound line.

--To change to 50-pound line.

--Divide the old line weight by the new line weight as a percentage: 30/50 = 60%.

--Multiply this percentage by your old line capacity: 60% x 450 yards = 270 yards (your new line capacity).

Amazingly (to me, anyway) this same formula works regardless of whether you're going up or down in line weight, and remarkably, the average error of all the 136 reel capacities I analyzed was only about 5%. The maximum error of any published set of numbers I tested was 16%. Most were about 7% or less.

Here's the simple but useful formula for figuring line capacities for all your Mexico fishing reels:

(Old Weight/New Weight) x Old Capacity = New Capacity.

(Related Mexico articles and reports may be found at's main Mexico information page. See weekly fishing news, photos, and reports from the major sportfishing vacation areas of Mexico including the Mexico area in "Mexico Fishing News.")