Quantity Converter (pieces, pairs, dozens, scores, gross)

Understanding the quantity converter — concept and principle

This converter changes counts between pieces, pairs, half dozens, dozens, baker's dozens, scores, gross and great gross. It shows the result, the count in pieces, dozens, gross and scores, and the number of whole dozens with pieces left over. Shopkeepers, bakers, craft buyers and anyone ordering small items in bulk use it.

Counting in dozens — with the default inputs: 20 dozen + 10.

How it is calculated

Unit sizes: pair 2, half dozen 6, dozen 12, baker's dozen 13, score 20, gross 144 (12 dozen), great gross 1,728 (12 gross)
Pieces = quantity × size of the "from" unit
Result = pieces ÷ size of the "to" unit
Whole dozens = ⌊pieces ÷ 12⌋; pieces left over = pieces mod 12

The principle

These counting units are fixed multiples of single items, so converting means multiplying to pieces and dividing again. The dozen-based units (dozen, gross, great gross) come from counting in twelves, which divides evenly by 2, 3, 4 and 6 and suits packing. A baker's dozen is 13. A score, 20, survives in phrases like "four score". Gross and great gross are still used for small items bought in bulk, such as pencils, screws and buttons. In Korean, a dozen is often called 타 or 다스.

Worked example

Defaults: 250 pieces to dozens.

Pieces = 250 × 1 = 250.
Dozens = 250 ÷ 12 = 20.833333 dozens (20.833).
Gross = 250 ÷ 144 = 1.7361; scores = 250 ÷ 20 = 12.5.
Whole dozens = 20 and 250 − 240 = 10 left: 20 dozen + 10 pieces.

Each point is the calculator re-run with only “Number of items” changed; the gold point is the default example. Change the inputs above and this chart follows your numbers.

Number of items	Result
62.5	5.2083333 dozens
125	10.416667 dozens
188	15.625 dozens
250	20.833333 dozens
312	26.041667 dozens
375	31.25 dozens
500	41.666667 dozens

How to read the result

When buying by the dozen or gross, round up to cover the pieces left over. When selling, the leftover count tells you how many items will not fill a full pack.

Common mistakes

Treating a gross as 100 instead of 144.
Confusing a baker's dozen (13) with a dozen.
Rounding the dozens before working out the leftovers.
Assuming a "pair" means two separate items when the product is sold as a single pair.

Keep in mind: Some trades use their own pack sizes; check the supplier's definition before ordering.

Frequently asked questions

How many items are in a gross?

144, which is 12 dozen.

What is a baker's dozen?

Thirteen.

How many dozens are 250 items?

20 dozen with 10 left over.

Sources: Merriam-Webster Dictionary, entries "dozen", "baker's dozen", "score", "gross" and "great gross"

Checked 9 Nov 2026. Merriam-Webster Dictionary, entries “dozen” (a group of 12), “baker’s dozen” (thirteen), “score” (twenty), “gross” (an aggregate of 12 dozen things) and “great gross” (a unit of quantity equal to 12 gross).

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