Units of measure: buy by the roll, sell by the foot

"We sell it and stock it by the foot, but we buy it by the tail, which is like 40 feet."

That's a store owner describing a single product, a length of chain, and the three units attached to it before anyone has even cut a piece. The vendor ships tails. The counter sells feet. The back room counts whatever is hanging on the hook that day, and hopes it reconciles. The same product shows up all over your store in different disguises: a box of twelve fasteners that sells one at a time, a ton of feed that is really forty fifty-pound bags, a reel of wire that is really 250 one-foot pieces standing in a trench coat. Every independent hardware, electrical, farm and feed, and garden store lives with this, and most inventory systems make it harder than it has to be.

The fix comes down to one sentence: one product, one base unit, and every other unit defined as a conversion back to that base. The base unit is the smallest quantity you ever sell, a foot of wire, a single screw, one bag of feed. The reel, the box, and the ton stop being separate things and become math on the product. Once that's true, your counts make sense, your reorder points see everything, and "can't you just tell it an item, we sell it by the foot and buy it by the roll, and it'll take care of the rest?" stops being a wish and starts being how the software works.

Why two SKUs for one product goes wrong

The most common workaround is the one a feed store owner described to us: "We have a product we sell by the bag or by the ton, we have two different numbers for that." Two SKUs for one physical pile of feed feels like a solution because each unit gets its own price and its own count. In practice it manufactures five problems at once.

The counts never agree. The box SKU says 3 and the each SKU says 7, and now nobody on earth knows how many screws are in the building. Every inventory count turns into a conversion exercise done on the fly, and every count done on the fly is a count with errors in it.

Reorder points go blind. The min/max on the each SKU has no idea the box SKU exists, so the system tells you to reorder fasteners while a full case sits in the back room under a layer of dust. You order product you already own, or you stop trusting the reorder report and go back to walking the aisles, which is the job the report was supposed to do.

Sales history splits in two. Half the volume lands on one SKU, half on the other, and both records look like slow movers. Your inventory turns on that product are a fiction in both directions, and when it's time to decide what earns its shelf space, the product that's actually moving looks like dead stock.

Receiving becomes a coin flip. The vendor ships a box. Depending on which clerk is on the desk and what day it is, that box gets received to the box SKU, or broken open mentally and received to the each SKU. Either way, one of the two records is now wrong, and the error compounds every truck day.

Margin drifts. The cost per each has to be recomputed from the box cost by hand, and hand-computed costs don't get recomputed. The box cost goes up in March, the each price stays where it was, and by fall you've been quietly selling screws below your intended margin for two quarters. Nothing was stolen. The inventory just leaked through the math.

The five flows a unit has to cover

The reason one product ends up wearing so many units is that a product isn't one transaction. It's five, and each one has its own natural unit:

The 250-foot reel is the classic illustration. An electrical distributor lists the same cord at $1.64 a foot and $409.16 a reel, because the reel price is just the foot price times 250. Same product, two units, one honest relationship between them.

A good setup doesn't fight this. It names a default unit for each flow and one conversion factor back to the base unit, then lets the five flows disagree with each other all they want, because they all reconcile to the same number. You stock in feet, price per foot, sell feet at the counter, order reels from the vendor, and transfer feet between stores. The only place a reel exists as a number is on the purchase order, where it belongs.

How to set up six common kinds of products

Wire, rope, and chain by the foot, off a reel

The standard setup, and the one the security and electrical trades converged on years ago: stock per foot, enter the purchase order by the box or reel, derive the cost per foot from the reel price, and sell by the foot on the ticket. A 250-foot reel arrives, the system adds 250 feet to on hand, and the counter never has to think about reels again. The alternative, stocking in reels and selling fractional reels, works too, but only if your counter staff enjoys typing 0.0588 into a quantity field. Label the per-foot price on the rack and the customer can do their own math, which they will do anyway.

Fasteners by the each, bought by the box

Stock each, sell each, order by the box with one conversion, say 1 box = 12 each. When the box arrives, receiving adds 12 to on hand and the reorder point sees it immediately, because there's only one record. If your vendor also has a case (say, twelve boxes), that's what case quantity is for: it rounds your purchase order up to full cases so you don't order a third of a shipping carton. A case is a rounding rule on the order, not a unit you sell in. The customer at the counter who wants "a whole box of those" gets twelve eaches at whatever price you've set, not a trip into your purchasing logic.

Feed by the bag or by the ton

Stock, price, and sell by the bag (or the pound), and order by the ton, with one conversion doing the work: 1 ton = 40 fifty-pound bags. The ton never needs its own SKU because the ton is just forty of the thing you already count. When a cattle customer buys a full pallet, the counter rings forty bags, or one ton that converts to forty bags, and the count drops by exactly forty either way. This is the setup that retires the "two different numbers" problem for good.

Bulk by weight or by the yard

Mulch, gravel, seed, and feed ingredients sold off a scale or a loader bucket need one thing most products don't: decimal quantities. Nobody buys exactly one cubic yard of mulch, and your scale ticket says 1.35. Turn decimals on for those products, let the scale or the bucket be the measuring device, and stock in the same unit you price in, per pound or per yard. There's more on this in our piece on feed store POS for bulk by weight and delivery, because bulk adds delivery and lot tracking on top of the unit question.

Cut-to-length and the remnant problem

Selling 14.7 feet of rope off a reel is the easy half. The hard half is the 3 feet left on the reel at closing time. That remnant is still inventory, and your setup decides whether it stays visible or falls into the void. Stocking in feet handles it naturally: the reel's balance just keeps shrinking, foot by foot, until it hits zero, and the count at month end matches the hook. Stocking in reels means the remnant shows up as 0.012 reels, which is technically correct and practically unreadable. Lineal goods like rope, chain, and wire are where a stocking-in-feet decision earns its keep, and lumber yards have their own version of this with tallies and board feet (plus a board-foot calculator if you need the conversion itself).

Paint sundries and caulk by the case

Caulk, rollers, and sundries usually want to be stocked and sold by the each but ordered by the case, and occasionally sold by the case too when a contractor wants a whole sleeve for a job. Stock each, order by case, and handle the case sale as an alternate price on the each rather than a second unit with its own inventory. The case price doesn't have to be exactly twelve times the each price, and usually isn't, because the whole point of selling a case is passing along the handling you didn't have to do. That's a pricing decision, and it belongs in pricing, not in your SKU list.

Counting when you stock by the reel

Whatever you pick as the stocking unit is what your inventory counts will ask for, so pick the unit your staff can actually count on a ladder at seven in the morning. A store that stocks wire by the reel counts reels, decimals allowed if you've enabled them. A store that stocks by the foot counts feet, which means measuring or estimating what's left on each reel, which means your cycle counts are only as good as your tape measure habits.

This is also where conversions quietly become shrink. A wrong factor (1 box = 10 instead of 1 box = 12) bleeds inventory that no thief ever touched, and an uncalibrated scale does the same thing a quarter pound at a time. By year end, the discrepancy looks like shoplifting and acts like shoplifting on your P&L, but it was arithmetic the whole time. We wrote about how that plays out in retail shrink for hardware and feed stores, and the short version is that conversion errors are some of the most fixable shrink you'll ever find. If your reorder points are also drifting, the reorder point and safety stock formula only works when the on-hand number feeding it is honest.

Conversions and your distributor's EDI

One more wrinkle: your vendors don't share your units. A distributor's electronic order can come back in boxes where your product is stocked in eaches, and one vendor's "box" is another vendor's "piece" for the exact same UPC. When an EDI 810 invoice or an advance ship notice lands in boxes and your shelf thinks in eaches, somebody has to convert, and if that somebody is a clerk with a calculator, you're back to the five failures above. The conversion has to live on the product, tied to the vendor's unit, so the receipt lands in the right unit without anyone translating by hand. This is a place where the details matter enough that it's worth asking any POS vendor exactly how their system maps a vendor's units to yours, and what happens when two distributors disagree about what a "box" is.

How Rundoo sets up units

Rundoo is the AI-first POS for independent supply stores, running in 500+ stores across the US and Canada, and units of measure are built as conversions on a single product record rather than as duplicate SKUs. Here's the setup, including the parts we're still working on.

You start with a company-wide list of units in Admin > Product > Units of measure. It isn't a fixed list: add whatever you count in, from EA, PC, FT, LF, BF, and MBF to roll, reel, box, bag, ton, yard, and pallet. On each product, Settings > Units of measure holds the unit conversions (each one a factor back to the base unit) and the defaults for the five flows: Stocking, Pricing, Sale, Order, and Transfer. Units can arrive with a vendor catalog import or by CSV, so you're not typing conversion factors one product at a time when you've got thousands of SKUs to set up.

Decimal quantities are a per-product switch, "Allow decimal quantities," so 14.7 feet of decking is fine on a sale line and 2.5 faucets is not. Counts, receiving, and transfers all happen in the stocking unit: stock by the reel and you count reels (with decimals if enabled), stock by the foot and you count feet.

Pricing follows the base unit through the conversion by default, and labels print the per-foot price when the Pricing default is FT. When a unit shouldn't simply be twelve times the each, you can unlink it and give it its own tier prices under Pricing > Alternate pricing, and if you want the counter to be able to switch the pricing unit on a sale, "Allow separate pricing unit selection in sales cart" handles that. Quantity breaks can be set per unit, so the contractor buying a whole case gets case pricing without anyone creating a case SKU. The pricing and purchasing page shows where all of this lives.

For the cases above: fasteners run as stocking EA, sale EA, order BOX with 1 BOX = 12 EA, and the Case quantity field on the Inventory tab rounds purchase orders to full cases (a rounding rule, not a selling unit). Feed runs stock, price, and sell by the bag or pound with order by the ton at 1 ton = 40 bags. For lineal goods, tally products offer three tally types, Length, Unified length, and Area, so mixed lengths can sit on one line with the total expressed in the product's unit, the same idea behind our lumber yard POS and inventory tools.

Now the plain limits. Fractions on a sale line aren't supported: a glass and metal shop that needed to sell 10 feet 3 inches as a fraction had to add inch as a unit and enter it as 123 inches, which works but asks the counter to multiply by twelve in their heads. On the EDI side, unit alignment with distributor catalogs has had an engineering fix, but edge cases where one distributor sends boxes and another sends pieces for the same product are still being worked through. And on cost: when a box carries its own alternate price, the cost side needs care, because a mis-set conversion can make margin read negative on a product that's actually making money. Our support team's recommended setup for a box of four sleeves, after seeing one mis-configured, is stocking EA with 1 BOX = 4 EA, Case quantity of 1, and the box price under Alternate pricing, with a second set of eyes on the cost. Unit conversions live on the product record and apply at every location, so a multi-store operation runs one shared definition.