Short answer: A round cotton module from a John Deere module-building harvester weighs roughly 4,500 to 5,500 pounds of seed cotton, according to USDA-ARS engineers writing in the Journal of Cotton Science. Moisture pushes a full-size module as high as about 5,700 pounds. One round module makes about 3 bales of lint if the cotton was stripped and about 4 bales if it was spindle-picked. A conventional rectangular module is much bigger: 18,000 to 22,000 pounds of seed cotton.
Three kinds of cotton modules
Almost all seed cotton reaches U.S. gins in one of three packages, as described in the Cotton Ginners Handbook chapter on seed cotton unloading (Funk and Wanjura, 2017):
| Module type | How it's made | Size | Seed cotton weight |
|---|---|---|---|
| Conventional (rectangular) | Tractor-powered module builder at the field edge | 32 ft long, about 7.25–7.5 ft wide, up to 8.5 ft tall | 18,000–22,000 lb |
| Half-length rectangular | Built on board a Case IH Module Express harvester | 16 ft long, 8 ft wide and tall | 12,000–13,800 lb |
| Round | Built and wrapped on board a John Deere harvester (7760, CP690, CS690 and later models) | 8 ft wide, 7.5–8 ft diameter | about 4,500–5,500 lb |
Two Case IH half-modules make roughly the same package as one conventional module and can be handled with the same equipment.
The conventional module dates to the early 1970s, when Lambert Wilkes at Texas A&M and J.K. "Farmer" Jones at Cotton Incorporated developed the system. Round modules arrived about 2009 and spread fast. A 2023 Journal of Cotton Science paper on unwrapping round modules says more than 50% of U.S. cotton is now harvested with John Deere module-building models.
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How much does a round cotton module weigh?
The numbers from published research line up closely:
- 4,500 to 5,500 lb (2,040–2,500 kg) for round modules 8 ft wide and 7.5 to 8 ft in diameter (Funk and Wanjura, 2017).
- 2,000 to 2,600 kg, or about 4,400 to 5,700 lb, for a full-size round module 2.44 m in diameter and 2.39 m wide, "depending on moisture content" (Delhom et al., 2023).
Two things move the weight. The first is moisture: wetter seed cotton weighs more. The second is module size. Operators can build smaller modules, and stripper cotton carries more burs and sticks, so the same size module holds less lint.
Round modules are also denser than conventional ones. An Australian study in the Journal of Cotton Science measured round modules at 180 to 240 kg per cubic meter, compared with 135 to 185 kg per cubic meter for conventional modules.
How many bales are in a round module?
Delhom and co-authors put it simply: a full-size round module produces approximately three bales of lint from stripper-harvested cotton and four bales from spindle-picked cotton. Australian research on picked cotton reports 3.5 to 4.5 bales per round module, depending on module weight, turnout and final bale weight at the gin.
You can check those numbers with turnout, the share of seed cotton weight that comes out of the gin as lint. USDA research on the Texas High Plains found picked cotton averaging about 35% turnout and stripped cotton about 30% with a field cleaner. U.S. production is counted in 480-pound bales.
Bales per module = module weight × turnout ÷ 480
| Seed cotton in module | Turnout | Lint | Bales (480 lb) |
|---|---|---|---|
| 4,500 lb | 30% (stripped, field-cleaned) | 1,350 lb | 2.8 |
| 5,000 lb | 30% | 1,500 lb | 3.1 |
| 5,000 lb | 35% (picked) | 1,750 lb | 3.6 |
| 5,500 lb | 35% | 1,925 lb | 4.0 |
| 5,500 lb | 38% | 2,090 lb | 4.4 |
Real bales off the press run slightly heavier than 480 pounds. The 2025 U.S. average was 491.5 pounds per running bale, according to NASS. For the full turnout math, see cotton gin turnout explained.
Conventional modules
The same math on a conventional module gives a much bigger number. At 20,000 pounds of seed cotton and 35% turnout, a conventional module makes about 14.6 bales. At 30% turnout, it's about 12.5. Australian research on conventional modules reported 12,000 to 16,000 kg modules averaging about 24 bales, but Australian modules are built larger than the U.S. dimensions above, so that figure doesn't carry over directly.
The U.S. cotton bale
The bale is the unit everything else is measured in. USDA reports cotton production in 480-pound net weight bales. It's a reporting unit, not an exact weight: the gin weighs every bale, and the actual weights vary around that figure.
Each bale also gets a Permanent Bale Identification (PBI) tag. The gin pulls a sample from every bale and sends it, with the tag, to a USDA classing office. Gins can also ask USDA to report quality as a module average. The classification record shows the module number and how many bales came from that module.
How many round modules per acre?
Divide your bales per acre by bales per module.
- A picked field making 1,200 pounds of lint per acre (2.5 bales) at about 4 bales per module needs a round module for every 1.6 acres.
- A stripper field making 600 pounds per acre (1.25 bales) at about 3 bales per module makes a module every 2.4 acres.
For yield by region, see how many bales of cotton per acre Texas makes.
Hauling round modules
Round modules don't need a tractor-pulled builder or a ground crew to tarp them, since the harvester wraps each one in plastic film as it goes. Moving them does take heavier equipment. Funk and Wanjura describe a tractor of about 360 horsepower with forks, clamps, spears or a grappling device to stage and load them. They recommend staging round modules end to end with a 6- to 8-inch gap between them for loading.
On the road:
- Up to 8 round modules fit on a flatbed semitrailer, and up to 10 on a set of double semitrailers, without special permits.
- Module trucks built for conventional modules can carry round ones if their chains have puncture-resistant or rounded lugs, so the wrap isn't torn.
At about 5,000 pounds each, eight modules is roughly 40,000 pounds of seed cotton on one trailer.
Moisture, storage and plastic wrap
Moisture is the main storage risk. Research cited in the Journal of Cotton Science found that seed cotton stored in conventional modules above 13% moisture suffered lint quality loss, while modules below 12% kept their quality. Color damage became likely above 11% moisture, especially when storage went past 45 days. The same researchers note that round modules need extra attention so rainwater doesn't pool in the bottom lip of the wrap.
The wrap itself is the other concern. Each wrap is about 21 meters of polyethylene weighing 4.5 kg, applied in at least three layers, with RFID tags built in. Gins cut it only in the zone the manufacturer marks, to avoid leaving loose pieces in the seed cotton. Plastic that reaches a bale is costly. On the USDA loan schedule for 2025-crop upland cotton, plastic extraneous matter carries a discount of 4,000 points, which is 40 cents per pound.
For field handling tips, see best practices for round cotton module handling. To follow a module through the plant, see how a modern cotton gin works.
Find a gin for your modules
The Texas South Plains, where much of the USDA turnout research above was done, is one of the busiest ginning regions in the country. Gin pages for the region:
- Cotton gins in Lubbock County, TX, including Lubbock Cotton Growers and City Gin in Abernathy
- Cotton gins in Hale County, Texas
- Cotton gins in Floyd County, Texas
- Cotton gins in Crosby County, TX
- Cotton gins near Lubbock and the South Plains
Cotton markets, every trading day. Know what is in the field and what it is worth: The Cotton Wire. Subscribe to The Cotton Wire
FAQ
How much does a round cotton module weigh?
About 4,500 to 5,500 pounds of seed cotton, per USDA-ARS. Wetter full-size modules can reach about 5,700 pounds (2,600 kg).
How many bales of cotton are in a round module?
About 3 bales for stripper-harvested cotton and about 4 for spindle-picked cotton. Heavier modules with high turnout can make 4.5 bales.
How much does a conventional cotton module weigh?
A standard 32-foot conventional module holds 18,000 to 22,000 pounds of seed cotton. A Case IH half-length module holds 12,000 to 13,800 pounds.
How many bales are in a conventional cotton module?
Roughly 12 to 15 bales, depending on module weight and turnout. For example, 20,000 pounds of seed cotton at 35% turnout makes about 14.6 bales.
How much does a bale of cotton weigh?
USDA reports production in 480-pound net weight bales. Actual running bales averaged 491.5 pounds nationally in 2025.
How many round modules fit on a truck?
Up to 8 on a flatbed semitrailer, or up to 10 on double semitrailers, without special permits.
Sources
- Funk, P. A., and J. D. Wanjura. "Seed Cotton Unloading Systems." Journal of Cotton Science 21:51–59 (2017), Cotton Ginners Handbook series: conventional, Case IH and round module dimensions and weights; history; staging and transport. https://doi.org/10.56454/zjjg4144
- Delhom, C. D., M. H. J. van der Sluijs, J. D. Wanjura, and J. W. Thomas. "Evaluation of Practices to Unwrap Round Cotton Modules." Journal of Cotton Science 27:90–101 (2023): full-size round module weight, bales per module by harvest type, U.S. adoption, wrap length, weight and layers, plastic contamination. https://www.cotton.org/journal/2023-27/2/upload/JCS27-090.pdf
- "The Effect of Round Module Storage Time and Ambient Conditions on Cotton Quality." Journal of Cotton Science (2025): round vs conventional module density; 3.5–4.5 bales per round module; moisture thresholds from earlier U.S. research. https://journal.cotton.org/wp-content/uploads/2025/12/JCS24-211.pdf
- Inside Cotton (Australian cotton research library). Round vs conventional module trial final report (CMSE1213): module weights and average bales per module. https://www.insidecotton.com/sites/default/files/article-files/CMSE1213_Final_Report.pdf
- Wanjura, J. D., W. B. Faulkner, E. M. Barnes, G. A. Holt, and M. G. Pelletier. "Crop Residue Inventory Estimates for Texas High Plains Cotton." Proceedings of the 2012 Beltwide Cotton Conferences, pp. 542–552: turnout by harvest method. https://www.cotton.org/beltwide/proceedings/2005-2022/data/conferences/2012/papers/13220.pdf
- USDA NASS. Cotton Ginnings 2025 Summary (May 2026): average net weight per running bale, 491.5 lb. https://esmis.nal.usda.gov/sites/default/release-files/795901/ctgnan26.pdf
- USDA NASS. Crop Production 2025 Summary (January 2026): production reported in 480-lb net weight bales. https://www.nass.usda.gov/Publications/Todays_Reports/reports/cropan26.pdf
- USDA AMS. Cotton Classification: Understanding the Data (updated July 13, 2018): PBI tags, bale samples, module averaging. https://www.ams.usda.gov/sites/default/files/media/CottonDBUnderstandingtheData.pdf
- USDA FSA. 2025-Crop Upland Cotton Schedule of Premiums and Discounts (corrected April 21, 2025): plastic extraneous matter discount. https://www.fsa.usda.gov/sites/default/files/2025-04/2025%20Cotton%20Loan%20Schedule%20CORRECTED%20APR212025.pdf
