About

Inventory management in manufacturing and hardware retail often relies on weight-based counting to save time. Counting thousands of small items like screws, washers, or electronic components individually is inefficient and prone to human error. This tool replicates the function of an industrial "Counting Scale," allowing users to determine quantity by dividing the total mass by the unit mass.

Precision is paramount here. A slight deviation in the "Unit Weight" can lead to significant discrepancies over large batches. This calculator uses a floor function to ensure results represent whole, complete items, preventing fractional errors in stocktaking. It is specifically designed for warehouse managers, hardware store clerks, and hobbyists managing bulk supplies.

Formulas

To calculate the total count of pieces from a bulk weight, the calculator employs simple division followed by a floor function to handle weight variances and partial broken pieces.

N = floor(W_totalw_unit)

Where:

N is the total number of whole pieces.
W_total is the total weight of the batch (converted to the same unit).
w_unit is the weight of a single piece.
floor rounds down to the nearest integer.

Reference Data

Item Category	Item Name	Approx Unit Weight (g)	pcs per 1 kg
Fastener	M3 Nut (Zinc)	0.3 g	~3,333
Fastener	M6 Washer (Flat)	1.1 g	~909
Fastener	M6 Bolt (20mm Hex)	8.5 g	~117
Fastener	M8 Bolt (30mm Hex)	19.2 g	~52
Fastener	M10 Bolt (50mm Hex)	46.5 g	~21
Currency	Euro Coin (1€)	7.5 g	133
Currency	US Quarter (25¢)	5.67 g	176
Stationery	A4 Paper (80gsm)	4.99 g	200
Construction	Standard Red Brick	2,300 g	0.43
Electronics	18650 Battery	45.0 g	22
Toy	LEGO 2x4 Brick	2.32 g	431
Metal	Steel Ball (1/2 inch)	8.4 g	119

Frequently Asked Questions

Inventory tracking requires counting whole, usable items. If the math results in 100.9 items, you only have 100 complete items. The 0.9 represents either weight variance or a broken/incomplete piece, which cannot be sold or used as a full unit.

It depends entirely on the consistency of the items. Manufactured metal parts (bolts, coins) are highly consistent, offering 99.9% accuracy. Organic or rough materials (wood, stones) have high variance, making this method less reliable.

Yes. This is called the "Tare" weight. You must weigh the empty container first and subtract that from your total weight before entering the value into the "Total Weight" field, or the count will be inflated.

Yes. Select "Custom Manual Input" from the dropdown menu. This unlocks the unit weight field allows you to enter the specific weight of any unique item you are counting.