When you sell honey, jam, salsa, maple syrup, or anything scooped into a tub, the thing on the scale is never just the product. It's the product plus the jar. And glass is heavy.
If your till weighs what's on the scale and charges for all of it, every customer buying a jar of honey is also paying — at your product's per-pound price — for an empty glass jar they'd have paid pennies for at a hardware store. On a slow afternoon with a cashier standing there, you catch it and zero the scale. At a self-serve stand with nobody at the counter, you don't catch it at all. It just quietly overcharges, jar after jar, until a regular does the math and stops trusting the scale.
The fix is a container weight — often called a tare — set once on the product, so the till takes the jar back off every time without anyone having to remember.
The jar is a bigger number than people think
Here's the part that surprises sellers: for dense products in glass, the container can cost the customer almost as much as the product.
Take honey at an example price of $9 a pound, sold in a jar that weighs half a pound empty. A customer buys a jar holding one pound of honey. On the scale, that reads 1.5 lb — the honey plus the glass.
That's $4.50 of overcharge on a single jar — half again the price of the honey — for glass the customer is going to recycle. Sell 60 jars across a season and, if you never take the jar off, you've charged your customers about $270 for empty glass (60 × $4.50). That's not a rounding error. It's the kind of thing a weights-and-measures inspector writes up, and the kind of thing a loyal customer notices and resents.
You could, of course, tare the scale by hand before each sale. That works when you're standing there. It does not work at 7 a.m. when the stand is open and you're not.
Set it once on the product, and the till remembers
The idea behind a preset container weight is simple: you tell the till, once, how much the jar for this product weighs. From then on, whenever that product is weighed, the till subtracts the jar automatically and charges for the net.
You set it in the product's own unit — if honey is priced per pound, you enter the jar weight in pounds. No scale zeroing, no mental math at the counter, no "fixed discount" hack that only works for one cup size.
Because the container weight lives on the product, a seller with several products in different jars doesn't juggle a list in their head. The pint of jam carries its jar weight; the quart of honey carries its own; the clamshell of tomatoes carries its clamshell. Each one is right the moment it's rung up.
When you don't know the exact jar weight, round up — in the customer's favour
Most sellers don't actually know what their jars weigh. So there's a built-in library of common containers — berry baskets, pint and quart jars, peck and bushel baskets, buckets, waxed boxes, clamshells — with typical weights you can drop onto a product as a starting point.
These are suggestions, not something the till applies behind your back. You pick one, and you can change it.
One deliberate choice worth calling out, because it reflects how we think you should treat customers: when the library gives a range for a container, the suggested default is the heavier end of that range — not the lighter end. The reasoning is one-directional. If your tare is a little too low, you've undercounted the jar and charged the customer for packaging — the exact thing you were trying to avoid. If your tare is a little too high, the only cost is a few cents of product you gave away. We'd rather the stand eat a few cents than a customer pay for an empty jar. A too-high tare is a rounding error in your favour-to-them; a too-low tare is the problem all over again.
If you want it exact — and for anything where the container really varies, like an absorbent pad under meat, you should — put an empty one on the scale and use Weigh it now. It captures the real weight and saves it to the product. (On a shared till, that's a managed action: it's recorded, so a weight didn't just change itself.)
The part no cashier-register tare can do: it holds when nobody's there
This is where a self-serve stand is different from a staffed shop, and where most point-of-sale tare features quietly stop being useful.
A built-in tare on a traditional register is a cashier action. Someone puts the item on the scale and taps "set tare." Fine — if there's a someone. At an unattended stand there isn't, so a cashier-only tare does nothing for you after hours.
A preset container weight is different because it's attached to the product, not to a person tapping a button. The jar comes off whether or not anyone is standing there. And at a self-checkout, the customer can't quietly remove it — the offset is respected and locked unless a manager steps in with a PIN.
| Staffed till | Self-checkout / unattended | |
|---|---|---|
| Who's weighing | You or your staff | The customer, or nobody |
| Container weight applied | Automatically, from the product | Automatically, from the product |
| Can it be changed on the spot? | Yes — no PIN; you're trusted at your own counter | No — a change needs a manager override with a PIN |
| If the scale might already hold a tare | Till warns you so you can check | Till keeps selling and still takes the preset off — it will never overcharge for packaging |
That last row is a specific decision, and it's the honest one for an unattended stand. If the till can't be sure whether the scale is already zeroed on a basket, the worst case it allows is giving away one basket's worth of product — never charging a customer for one. At a stand you can't babysit, "never overcharge" beats "squeeze the last cent" every time.
What about customers weighing their own goods?
Letting a customer put their own purchase on the scale is off by default, because it's a real decision, not a default-on convenience. When it's off, a weighed item at a self-checkout can't be added without a manager PIN at all — nobody's self-weighing honey unsupervised unless you turned it on.
When you do turn it on, two things can happen:
- With a scale connected: the scale's reading is what counts, and the container still comes off. The customer can't untick it.
- With no scale: the customer types the weight on the keypad — useful for u-pick, where they've filled their own bucket — and the container weight still comes off the number they typed. They can't keep the bucket in the price.
What it won't do, and what you still own
A container weight is honest about its limits, and so are we:
- It can't weigh a jar it's never met. The preset is your best estimate of a standard container. If a customer brings a wildly different jar from home, the preset is the wrong number for that one sale — use Weigh it now, or price it the old-fashioned way.
- It's your number, not ours. The library gives you a sensible starting point, but the only truly correct tare is the one you get by putting your empty jar on your scale. Do that once per container and you're set.
- Net-weight rules are a real thing. Selling by weight — especially food — usually means you're legally charging for net contents, not gross. Taking the container off is how you stay on the right side of that, but the specifics are set by your state's weights-and-measures or department-of-agriculture office, not by your till. If you're unsure how your state treats tare, ask them. The till makes doing it right easy; it doesn't make the rules.
Get the jar off your scale
If you sell anything by weight at a stand you can't always staff — honey, jam, syrup, bulk grains, coffee, flowers by the stem-weight, meat by the cut — a preset container weight is the difference between a scale your regulars trust and one they learn to work around.
TallyTill runs on a phone or tablet you already own, and the entry plan is free — no card to start. You can set a container weight on your first weighed product in about a minute.
- Create your free account and set up your first by-weight product.
- See what each plan includes on the pricing page.
- More field-tested guides for self-serve sellers are in the resource library.
Sell the honey. Give them back the glass.