Weighing liquor bottles for inventory
The method behind a weight-based stock take, step by step, and the mistakes that quietly spoil a count.
Why weigh bottles instead of reading the level
Reading a level depends on the shape of the bottle. A tall bottle and a squat one filled to the same height hold different amounts, and two people rarely read the same level the same way. Weight does not care about shape or lighting.
Weight also leaves a number you can store and compare. A glance at a bottle does not.
Weighing a bottle, step by step
The same six steps whether you do them on paper or let WeighIt do them.
| Step | By hand | With WeighIt |
|---|---|---|
| 1. Know the empty bottle weight | Weigh an empty bottle of each product and write it down | Stored per product when the product is calibrated |
| 2. Weigh the open bottle | Read the scale and note the grams | Scan the barcode and place the bottle on the Bluetooth scale |
| 3. Subtract the empty bottle | Open weight minus empty weight gives the weight of the liquid | Done by the app |
| 4. Convert weight to volume | Divide by the density of that product | Done by the app, using the product's figures |
| 5. Convert volume to tots | Divide by the size of a tot | Done by the app and shown as tots left |
| 6. Record and compare | Copy to a sheet, then compare with sales | Saved, and compared with sales in the variance report |
Mistakes that skew a weight-based count
- One empty weight for every bottle. Glass differs between brands and sizes, so each product needs its own empty weight.
- One density for every liquid. Spirits and liqueurs weigh different amounts per millilitre.
- Weighing differently each time. Use the same scale, the same surface and the same setup for every bottle, so differences in the count come from the stock and not from the method.
- Testing with a bottle you topped up by eye. The test then measures how well you filled it, not how well the method works. Top test bottles up by weight.
Setting a product up once
Each product is calibrated one time. After that, a bottle is one scan and one weighing.
Weigh a full bottle
A sealed bottle of the product gives the weight of the glass plus a known volume of liquid.
Weigh an empty bottle
The same product, emptied, gives the weight of the glass on its own. The difference is the weight of the liquid.
Save it
The app stores the figures it needs for that product. From then on, the product is ready to weigh.
If you have no empty bottle yet
A full and an empty bottle is the recommended way to calibrate, because it is more accurate. If you have no empty bottle yet, the app can also calibrate a product from a poured measure.
If a product is not in your catalogue, you can add it by weighing a full and an empty bottle and entering basic product information.
What WeighIt costs
We set everything up: your products loaded from your spreadsheet, a Bluetooth scale included and couriered to you, and step-by-step guides and video tutorials for your first stock take. No subscription required.
Monthly variance report against POS sales, unlimited products and users, and priority support. Month to month, no long-term contract.
Questions about weighing liquor bottles
How do you weigh liquor bottles for inventory?
Weigh the open bottle, subtract the empty bottle weight, convert the remaining weight to volume using the product's density, then convert volume to tots. WeighIt does each of those steps once a product has been set up.
Does bottle shape matter when weighing?
No. Weight does not depend on shape, which is why it works for tall, squat and square bottles where a level reading does not.
What if a product is not in the catalogue?
You can add it by weighing a full and an empty bottle and entering basic product information.
What scale do I need?
A supported Bluetooth scale. One is included and couriered to your site with the setup. It is standard off-the-shelf hardware.
Can I do this with a kitchen scale and a spreadsheet?
Yes, the method is the same. The cost is the arithmetic and the typing on every bottle. WeighIt captures the weight over Bluetooth and does the calculation.
How much does it cost?
The once-off setup, scale included, is R7,500 per site. The variance programme is then R4,000 per site per month.
Get the app and watch how it works
WeighIt runs on iPhone, Android and the web. The tutorial videos cover the setup, the scale and a full stock take.
Ask about WeighIt for your bar
Tell us your venue type and how many sites you run. We reply by email.