Grain Conversion Calculator

What Is a Grain Conversion Calculator?

A grain conversion calculator converts quantities of harvested grain between the measurement systems used in different parts of the global grain trade: US bushels, metric tonnes, short tons, long tons, kilograms, pounds, and hundredweight. Each grain has a different standard test weight (the legal weight of one bushel in pounds), which is the critical conversion factor that makes direct unit conversion impossible without knowing the specific crop.

Corn is 56 lbs per bushel. Wheat and soybeans are 60 lbs per bushel. Barley is 48 lbs per bushel. Oats are 32 lbs per bushel. Applying the wrong test weight produces systematic errors: converting soybean bushels as if they were corn bushels underestimates the weight by 6.7%. On a 50,000-bushel cargo, that is a 169-tonne discrepancy, enough to void a trading contract or trigger a margin call.

The bushel is a US volume measure standardised in the 19th century that has been converted into a weight measure by assigning a legal test weight per crop. The official US standards are set by the Federal Grain Inspection Service (FGIS) under the USDA. International trade, however, uses the metric tonne as the standard unit. Every bushel price quoted on the CBOT (Chicago Board of Trade) has an exact metric tonne equivalent that changes with each tick, and grain traders, merchandisers, elevator operators, and exporters perform these conversions dozens of times per day.

The USDA Agricultural Marketing Service grain standards define the official test weights and moisture standards used throughout this calculator.

How to Use the Grain Conversion Calculator

1. Select your grain. Choose from 14 common crops, each preloaded with its official USDA test weight and standard moisture percentage. If you have a grain with an unusual or variety-specific test weight (such as a high-test-weight wheat variety or a non-standard commodity), choose "Custom test weight" and enter the lbs-per-bushel figure from your grain buyer's contract or grain standards documentation.
2. Enter quantity and input unit. Type the quantity you want to convert and select the input unit from the dropdown: bushels, pounds, kilograms, metric tonnes, short tons (US), long tons (UK), or hundredweight (cwt = 100 lbs). The calculator converts to all other units simultaneously.
3. Apply moisture correction (optional). If your grain is above standard moisture at the time of weighing, the displayed weight is greater than the dry-matter equivalent. Open the Moisture Correction panel, enter the actual grain moisture percentage, and the calculator applies the standard shrinkage formula: corrected weight = actual weight × (100 − actual%) ÷ (100 − standard%). This gives you the settled weight after drying to standard moisture.
4. Convert prices (optional). Open the Price Conversion panel to convert between $/bushel, $/metric tonne, $/short ton, and $/long ton. Enter the price in any unit and all four equivalents display instantly. With a quantity entered, the calculator also shows the total lot value at that price.
5. Reference table. The collapsible table at the bottom shows test weights and standard moistures for all 14 supported crops as a quick reference without needing to switch the crop selector.

Formula and Methodology

All conversions route through pounds (lbs) as the common intermediate unit:

Pounds = bushels × test weight (lbs/bu)
Metric tonnes = pounds × 0.000453592
Kilograms = pounds × 0.453592
Short tons = pounds ÷ 2,000
Long tons = pounds ÷ 2,240
Hundredweight = pounds ÷ 100

Worked example: corn forward contract: A US elevator has a deferred delivery contract for 200,000 bushels of corn at $4.85/bu. The buyer is an EU importer who prices in €/MT.

• Total weight: 200,000 bu × 56 lbs/bu = 11,200,000 lbs
• Metric tonnes: 11,200,000 × 0.000453592 = 5,080.2 MT
• Price in $/MT: $4.85 ÷ (56 × 0.000453592) = $4.85 ÷ 0.025401 = $190.94/MT
• Total contract value: 200,000 × $4.85 = $970,000

Moisture correction: wet corn example: A combine delivers corn at 22% moisture. The elevator books the load at standard 15.5% moisture for payment purposes.

Shrink factor = (100 − 22) / (100 − 15.5) = 78 / 84.5 = 0.9231
Corrected bushels = 10,000 bu × 0.9231 = 9,231 bu
Weight lost to drying: 769 bushels worth of water removed

The farmer receives payment on 9,231 bushels, not 10,000. The 769-bushel shrinkage represents the water the elevator must dry out before the corn reaches storage or transportation standard. Some elevators charge an explicit drying fee instead of (or in addition to) reducing the settled bushel count; the moisture correction formula here calculates the weight-based shrinkage only.

Standard Test Weights and Why They Matter

The test weight of grain (how much a bushel weighs in pounds) is set by law in the United States and directly affects every weight-based grain transaction in the world. The key standards are:

• Corn: 56 lbs/bu (25.40 kg/bu), approximately 39.37 bu/MT
• Wheat: 60 lbs/bu (27.22 kg/bu), approximately 36.74 bu/MT
• Soybeans: 60 lbs/bu (27.22 kg/bu), same as wheat; 36.74 bu/MT
• Barley: 48 lbs/bu (21.77 kg/bu), approximately 45.93 bu/MT
• Oats: 32 lbs/bu (14.52 kg/bu), approximately 68.89 bu/MT
• Sorghum: 56 lbs/bu (same as corn)
• Canola/Rapeseed: 50 lbs/bu (22.68 kg/bu), approximately 44.09 bu/MT

These are the weights for grain grading at or above minimum quality standards. Low-test-weight grain (caused by disease, drought stress, premature frost, or poor growing conditions) has a lower actual lbs/bu and is typically discounted below the standard contract price. Grain graded "US No. 2 Corn" requires a minimum test weight of 54 lbs/bu; grain below 56 lbs/bu but above 54 lbs/bu trades at a discount but still converts at the actual measured test weight, not the 56-lb standard.

For the UK grain trade, the AHDB grain weights and measures guide sets the reference hectolitre weights used in EU and UK contracts, which are the metric equivalent of US test weights (kg per 100 litres).

Real-World Applications

Export merchandiser pricing a CBOT-based contract in metric tonnes: A UK grain trader buys US corn through a CBOT futures hedge at 480 cents/bu ($4.80/bu). Her buyer in Spain prices in €/MT. The price conversion gives: $4.80 ÷ (56 × 0.000453592) = $4.80 ÷ 0.02540 = $189.0/MT. With EUR/USD at 1.085, the price is €174.2/MT. The calculator also confirms the cargo size: 50,000 MT ÷ 0.025401 = 1,968,820 bushels of CBOT corn futures required to hedge the position. The grain conversion calculator makes this two-way translation instant and removes the rounding errors that accumulate across multiple manual calculations during fast-moving markets.

On-farm storage decision based on moisture cost: A Nebraska corn farmer harvests 80,000 bushels at 22% moisture. He must decide whether to dry at the elevator (receiving payment on the moisture-corrected settled bushels) or dry in his own on-farm bin and deliver at 15.5%. The moisture correction formula shows: settled bushels at elevator = 80,000 × (78/84.5) = 73,846 bu. Effective shrinkage: 6,154 bushels. At $5.10/bu, the shrinkage is worth $31,385. If the on-farm dryer can remove the moisture for less than $31,385 in propane and labour (typically $0.03–0.05/bu per point of moisture removal = 6.5 points × 80,000 bu × $0.04 = $20,800), drying on-farm and delivering at standard moisture is economically preferable. The calculator makes this comparison explicit.

Feed ration calculation in mixed units: A livestock nutritionist is formulating a blend using 2 metric tonnes of barley, 1.5 short tons of oats, and 500 kg of canola meal. To check the total ration weight and cost against a budget expressed in bushels, all three quantities need converting to a common unit. The calculator handles each conversion: barley 2 MT = 91.8 bu; oats 1.5 short ton = 2,000 × 1.5 / 32 = 93.75 bu; canola 500 kg / 22.68 kg per bu = 22.05 bu. Total: 207.5 bushels. Combined with the corn yield calculator and the GDU calculator for heat-accumulation-based yield forecasts, the grain conversion tool allows farm-level grain production and feed use to be tracked in consistent units across the whole operation.

Agricultural finance and lending: A farm lender needs to value a 150,000-bushel wheat bin at current market price for a line of credit calculation. The grain is at 14.5% moisture (above the 13.5% standard). Moisture-corrected bushels: 150,000 × (85.5/86.5) = 148,266 bu. At $6.20/bu, collateral value = $919,249. The 1,734-bushel shrinkage is worth $10,751, material at this scale. Lenders who skip the moisture correction systematically overvalue wet-grain collateral by 1–3%, which can accumulate to significant portfolio exposure across thousands of farm accounts.

Common Mistakes and Troubleshooting

Using the wrong test weight for the crop: The single most consequential error. Soybeans and wheat are both 60 lbs/bu, which makes them easy to confuse with each other but not with corn (56 lbs/bu) or barley (48 lbs/bu). Always confirm the test weight from the buyer's contract specifications or the official USDA grain standards for the crop year.

Confusing short tons with metric tonnes: A short ton is 2,000 lbs; a metric tonne is 2,204.6 lbs, which is 10.2% heavier. International cargo contracts and freight rates are almost always in metric tonnes. US domestic contracts often use short tons. Using the wrong unit means over- or under-delivering by roughly 200 lbs per tonne; on a 50,000 MT cargo that is 5,100 tonnes of grain, worth over $1 million at current corn prices.

Confusing metric tonnes with long tons: A long ton (UK) is 2,240 lbs versus 2,204.6 lbs for a metric tonne, a 1.6% difference. Older UK grain contracts occasionally specify long tons. Always clarify which "tonne" a contract refers to before signing.

Applying moisture correction in the wrong direction: The moisture correction formula reduces weight when actual moisture exceeds standard. If your grain is already at or below standard moisture, no correction is needed; the grain is already at full dry-matter weight. Applying the formula when actual moisture is below standard would increase the weight, which is incorrect in trade contexts (you cannot receive credit for drier-than-standard grain unless the contract specifically allows it).

Ignoring dockage in test weight: Grain containing significant foreign matter (dockage) is tested before and after cleaning. The pre-clean test weight includes the weight of weed seeds, broken kernels, and other material. Official grading uses the cleaned sample test weight, which will typically be higher than the field-run test weight. If your grain has significant dockage, the effective conversion factor changes after cleaning.