Counting Scale Buying Guide: How Counting Scales Work and Which One to Buy

A counting scale turns weight into a piece count: it learns the weight of one piece from a small sample, then divides the total weight by that average. Done right, it counts a bin of fasteners in seconds with the accuracy of a hand count. MNM Scales is an authorized A&D dealer and one of the largest scale distributors in the country, with over 30 years in business. This counting scale buying guide explains the specs that matter and gives our picks.

How a counting scale works

1. Tare the container. Place the empty bin or tray and press tare.
2. Sample. Add a set number of pieces (A&D models offer 5, 10, 25, 50, 100 or any number) and press the sample key. The scale calculates the unit weight (average piece weight).
3. Count. Pour in the rest; the display shows pieces, total weight and unit weight.
4. Improve accuracy. A&D’s ACAI (Automatic Counting Accuracy Improvement) recalculates the unit weight as you add pieces, reducing the error from a small sample.

Counting scale specs that matter

• Minimum unit weight: the lightest piece the scale can count. A&D lists a normal and a fine-mode value; keep your lightest part comfortably above it.
• Internal resolution: counting scales resolve far finer than the display. The A&D FC-i series uses an internal resolution of 1/1,000,000; the HC-i uses 1/600,000 (1/750,000 on the HC-15Ki).
• Readability and capacity: capacity sets the largest batch; readability sets how finely the total weight is shown (see d vs e on NTEP scales).
• Sample size: larger samples give a better average, especially when parts vary.
• Memory and data: stored unit weights, tares and limits save time on repeat parts. The FC-i stores 500 IDs, the GC 1,000 items (expandable with a MicroSD card) and the HC-i 99.
• Dual-scale counting: the FC-i and GC can connect a remote platform for bulk counting (options sold separately, not included).

Our picks: best counting scales by job

Scale	Capacity x readability	Minimum unit weight (normal / fine)	Best for
A&D FC-500Si	500 g x 0.02 g	0.001 g / 0.00005 g	The tiniest parts; uses A&D’s Super Hybrid Sensor
A&D FC-500i	500 g x 0.05 g	0.01 g / 0.0005 g	Electronic components, small screws, labels
A&D FC-2000i	2 kg x 0.2 g	0.04 g / 0.002 g	Small parts in larger trays
A&D GC-3K	3 kg x 0.5 g	0.1 g / 0.005 g	Kitting stations; 1,000-item memory, AIS item search
A&D FC-5000i	5 kg x 0.5 g	0.1 g / 0.005 g	Mixed small and medium parts
A&D GC-15K	15 kg x 2 g	0.4 g / 0.02 g	General stockrooms and receiving
A&D HC-15Ki	15 kg x 2 g (30 lb x 0.005 lb)	0.4 g / 0.02 g	Value counting with ACAI and 99 IDs
A&D FC-20Ki	20 kg x 2 g	0.4 g / 0.02 g	Bins of fasteners and hardware
A&D FC-50Ki	50 kg x 5 g	1 g / 0.05 g	Heavy bins and bulk parts

A&D values are from A&D’s published specifications; the minimum unit weight depends on an internal setting. Most counting work is inventory, not trade, so a general-purpose counting scale is fine. On a tighter budget, the Brecknell B140-30 (30 lb x 0.001 lb) has an internal rechargeable battery and stored part numbers (PLUs). If the count or weight is used to charge a customer, choose an NTEP model such as the OHAUS Ranger Count 3000 RC31P15 (30 lb x 0.001 lb, 0.01 lb in NTEP mode; see what NTEP means). Comparing OHAUS families? See OHAUS Valor vs Ranger vs Scout.

Tips for accurate counts

• Use a bigger sample when parts vary, such as molded or stamped parts.
• Keep the lightest part above the minimum unit weight, and use fine mode for very small parts.
• Count away from drafts and vibration, (the FC-500Si includes a breeze break).
• Re-sample each new lot, because piece weight can change between suppliers or production runs.
• Check the scale with a certified weight (see calibration weight classes and calibration weights, sold separately).

Calibration and service for counting scales

Counting accuracy depends on calibration, so calibrate at least once a year (see how often to calibrate). MNM Scales is TDA licensed with registered technicians and calibrates counting scales with in-house or NIST-traceable certificates (which certificate do you need?). On-site service in Houston and suburbs is a $295 service call plus $2 per mile round trip, and nationwide mail-in calibration usually takes 1 to 3 business days:

Frequently asked questions

How does a counting scale work?

You tare the container, place a known number of sample pieces and the scale calculates the average piece weight. It then divides the total weight by that average to show the piece count.

What is the minimum piece weight on a counting scale?

It is the lightest part the scale can count reliably. On the A&D FC-500i it is 0.01 g in normal mode and 0.0005 g in fine mode; on the GC-15K it is 0.4 g and 0.02 g.

What is ACAI on an A&D counting scale?

ACAI (Automatic Counting Accuracy Improvement) recalculates the unit weight as more pieces are added, which reduces the error that comes from a small sample.

How many pieces should I use for the sample?

Use at least the default 10 pieces, and more (25, 50 or 100) when parts vary in weight. A larger sample gives a better average piece weight.

Does a counting scale need to be NTEP?

Inventory counting does not set a price, so a general-purpose counting scale works. If the count or weight is used to charge a customer, choose an NTEP model.

Can MNM Scales calibrate my counting scale?

Yes. We calibrate counting scales with in-house or NIST-traceable certificates, on-site in Houston and suburbs or by nationwide mail-in, usually in 1 to 3 business days.