Three ounces in, one out
Start where the form starts: 80 oz of finished jerky, 12 percent trim off the raw cut, and a finished weight that is 38 percent of the sliced weight. Five pounds of jerky needs 13.16 lb of sliced meat, which needs 14.95 lb of roast at the till. That is 2.99 oz of raw beef per finished ounce.
The overall yield is 33.4 percent — and that is 88 percent times 38 percent, not 38 minus 12. Percentages taken in sequence multiply. Subtracting them gives 26, which would have you buy 19.23 lb of roast instead of 14.95 — four and a quarter pounds of beef too much.
What it does to the price
At 6.99 a pound the meat is 104.52 dollars. Four batches of marinade at 4.50 is 18.00, and 16.8 kWh at 15 cents is 2.52. That is 125.04 dollars for 80 oz, which is 1.563 dollars an ounce or 25.01 a pound of jerky.
Your 6.99 beef has become 25 dollar beef, a multiple of 3.6, and the multiple is set almost entirely by the shrink figure. The marinade and the electricity together are 20.52 dollars — 16 percent of the total — so they are worth including but they are not what makes jerky expensive. Water leaving is.
The comparison, and where it flips
A 2.85 oz bag at 8.99 is 3.154 dollars an ounce, so the same 80 oz over the counter is 252.35 — 29 bags, since you cannot buy part of one. Home wins by 127.31 dollars, just over half.
But that is a statement about prices rather than about jerky, so the page prints the crossover instead of a verdict. Holding the trim, the shrink, the marinade and the power fixed, the two land on the same money when the meat costs 15.50 a pound. Below that, making it is cheaper; above it, the bag is. Buying a lean cut at 17 dollars a pound because it trims tidily puts you on the wrong side of that line without it ever feeling like an expensive decision.
Measure the shrink and stop guessing everything else
Every other input on the form is a number you already know — what the meat cost, what the machine draws, what the bag was. The shrink figure is the one that decides the answer and the one nobody has weighed. Finishing at 34 percent instead of 38 takes the raw meat from 14.95 lb to 16.71 and the cost from 1.563 to 1.717 an ounce, a ten percent swing from four points.
Weighing it costs one batch of attention: put the sliced meat on the scale before it goes on the trays, put the jerky on the scale when it comes off, divide. After that the page is yours rather than generic, and the crossover it prints means something.
What is not in here
No time, no temperature, no view on how dry is dry enough, and no judgement about whether anything you make is safe to eat or to keep. Drying is one of the places where that question genuinely matters and it is not one a cost calculator can answer. Take it to a tested method you trust and to somebody qualified.
Questions people ask
How much meat does it take to make a pound of jerky?
At the figures in the form — 12 percent trim and a finished weight that is 38 percent of the sliced weight — it takes 2.99 lb of raw roast for one pound of jerky, so roughly three to one. Your own shrink figure moves it a lot: finishing at 34 percent instead of 38 pushes it to 3.34 to one. Weigh one batch in and out and you will have your own number.
Is homemade jerky cheaper than buying it?
At the default figures, yes, by about half: 125.04 dollars against 252.35 for the same 80 oz in 2.85 oz bags. But that is a statement about two prices, so the page prints the crossover instead — at these trim, shrink and running costs the two meet when the meat costs 15.50 a pound. Above that the bag wins, and expensive lean cuts get there faster than people expect.
Why is my jerky so expensive to make?
Because roughly two thirds of what you bought leaves as water. At the default figures 14.95 lb of roast becomes 5 lb of jerky, so a 6.99 dollar pound of beef turns into 25.01 dollars a pound of jerky, a multiple of 3.6. Marinade and electricity together are only 16 percent of the total. The shrink is the whole story.
Can I just subtract the trim and shrink percentages?
No, and it is a common way to be wrong by a pound and a half. They apply one after the other, so they multiply: 88 percent of the raw weight survives trimming and 38 percent of that survives drying, which is 33.4 percent overall. Subtracting 12 from 38 gives 26, which sends you to the counter for 19.23 lb instead of 14.95 — overstating the meat by nearly a third.
What shrink percentage should I use for beef jerky?
Your own, measured once. The field defaults to 38 percent as a placeholder to replace, and it moves with slice thickness, with grain direction, with your machine and with how dry you take it. Weigh the sliced meat before it goes on and the jerky when it comes off, divide, and use that. It is the only input on the page worth the trouble of measuring.