Grain Conversion Calculator

What is a Grain Converter?

A grain converter is an essential tool for the agricultural industry that translates quantities of grain between different units of measurement. Agricultural commodities such as wheat, corn, soybeans, oats, and barley are measured using a variety of units depending on the region, the purpose of the measurement, and the stage of the supply chain.

In the United States, the traditional unit for measuring grain is the bushel. Farmers sell their grain by the bushel, elevators receive and store grain measured in bushels, and futures contracts on the Chicago Board of Trade (CBOT) are priced per bushel. However, once grain enters international trade, metric tonnes become the dominant unit. Countries in Europe, Asia, South America, and Africa all transact in metric tonnes, and the global shipping industry quotes freight rates per tonne.

This creates a constant need for conversion. A farmer who harvests 10,000 bushels of soybeans needs to know how many metric tonnes that represents when negotiating an export sale. A commodity trader comparing prices between the Chicago and Paris exchanges must convert between bushels and tonnes. Feed mills, ethanol plants, and flour mills may purchase grain by the bushel but process it in pounds or kilograms.

Our grain conversion calculator bridges these measurement systems instantly. Simply select your grain type, enter a quantity in any supported unit, and receive the equivalent value in every other unit. Whether you are a farmer estimating your harvest value, a trader analyzing international markets, or a logistics coordinator planning shipments, this tool saves time and eliminates arithmetic errors.

How Much is a Bushel?

The bushel is one of the oldest units of measurement still in active commercial use. Originally, a bushel was a unit of dry volume equal to 8 gallons, or approximately 35.24 liters. The word itself dates back to the 14th century, derived from the Old French "boissel," a measure of grain.

In modern grain trading, however, the bushel is defined by weight rather than volume. This is a critical distinction. Because different grains have different densities, a volumetric bushel of wheat weighs considerably more than a volumetric bushel of oats. To standardize trade and avoid disputes, the United States Department of Agriculture (USDA) established official standard test weights for each grain commodity.

A standard test weight specifies how many pounds of a given grain are considered equivalent to one bushel. For example, the USDA defines one bushel of wheat as 60 pounds and one bushel of corn as 56 pounds. These weights assume grain at a standard moisture content, typically around 13.5% for corn and 13.0% for wheat.

The concept of test weight also serves as a quality indicator. Grain that meets or exceeds the standard test weight is generally denser, plumper, and of higher quality. Grain that falls below the standard test weight may be docked in price because it contains more air space, less starch, and may indicate poor growing conditions, disease, or excessive moisture.

Historically, the bushel as a volumetric measure varied from region to region. In England, the Winchester bushel (approximately 2,150.42 cubic inches) became the standard, and this is the basis of the US bushel. The Imperial bushel used in the United Kingdom and Canada is slightly larger at about 2,219.36 cubic inches. For grain trading purposes in the US, however, the weight-based definition has superseded volumetric measurement entirely.

Bushel Weights by Grain Type

The following table shows the standard USDA bushel weights for common grain commodities. These are the weights used in commercial trade, futures markets, and by grain elevators across the United States.

These weights are standard reference values. Actual grain delivered to an elevator may have a slightly different test weight depending on moisture content, growing conditions, and grain variety. Elevators will measure the actual test weight at delivery and adjust the effective bushel count accordingly.

How to Convert Bushels to Pounds

Converting bushels to pounds is straightforward once you know the standard weight per bushel for your grain type. The formula is:

Pounds = Number of Bushels x Weight per Bushel (lbs/bu)

Here is a step-by-step example for wheat:

1. Determine the grain type: Wheat
2. Look up the standard bushel weight: 60 lbs per bushel
3. Multiply your bushel quantity by the weight: 500 bushels x 60 lbs/bu = 30,000 lbs

So 500 bushels of wheat equals 30,000 pounds. For corn at 56 lbs per bushel, 500 bushels would equal 28,000 pounds. For oats at 32 lbs per bushel, the same 500 bushels would equal only 16,000 pounds.

To convert in the opposite direction (pounds to bushels), simply divide the total pounds by the weight per bushel:

Bushels = Total Pounds / Weight per Bushel (lbs/bu)

For example, 45,000 pounds of soybeans at 60 lbs/bu = 750 bushels.

How to Convert Bushels to Metric Tonnes

Converting bushels to metric tonnes is a two-step process. First, convert bushels to pounds using the grain's standard bushel weight. Then convert pounds to metric tonnes using the conversion factor 1 metric tonne = 2,204.62 pounds.

Step 1: Bushels to Pounds: Pounds = Bushels x lbs per bushel

Step 2: Pounds to Metric Tonnes: Metric Tonnes = Pounds / 2,204.62

Here is a worked example for corn:

1. Start with 1,000 bushels of corn
2. Convert to pounds: 1,000 x 56 = 56,000 lbs
3. Convert to metric tonnes: 56,000 / 2,204.62 = 25.40 metric tonnes

This means 1,000 bushels of corn is approximately 25.40 metric tonnes. For quick reference, here are some common conversion factors per 1,000 bushels:

• Wheat: 1,000 bu = 27.22 metric tonnes
• Corn: 1,000 bu = 25.40 metric tonnes
• Soybeans: 1,000 bu = 27.22 metric tonnes
• Barley: 1,000 bu = 21.77 metric tonnes

Conversely, to convert metric tonnes back to bushels, multiply by 2,204.62 to get pounds, then divide by the bushel weight. For example, 100 metric tonnes of wheat = 220,462 lbs / 60 lbs/bu = 3,674.37 bushels.

Grain Bin Capacity Calculator

Knowing the storage capacity of your grain bins is essential for harvest planning, inventory management, and insurance purposes. The capacity of a cylindrical grain bin is calculated using a simple geometric formula.

The volume of a cylinder is:

Volume (cubic feet) = pi x r² x h

Where r is the radius of the bin (half the diameter) and h is the height of the grain inside the bin. Since one bushel of grain occupies approximately 1.244 cubic feet, you divide the total volume by 1.244 to get the capacity in bushels:

Bushels = (pi x r² x h) / 1.244

Let us walk through an example:

1. Bin diameter: 18 feet, so radius = 9 feet
2. Grain height: 12 feet
3. Volume = 3.14159 x 9² x 12 = 3.14159 x 81 x 12 = 3,053.63 cubic feet
4. Bushels = 3,053.63 / 1.244 = 2,454.49 bushels

This formula assumes the grain is level (no peaked cone at the top). If grain is peaked, additional volume in the cone must be calculated separately using the formula for a cone: Volume = (1/3) x pi x r² x peak height.

Keep in mind that this gives the theoretical maximum capacity. In practice, you may not fill a bin completely to account for aeration space, unloading equipment, and safety margins. Most operators plan for about 90-95% of theoretical capacity as usable storage.

How Accurate is This Grain Calculator?

This calculator uses the official USDA standard test weights for each grain type, which are the same weights used in commercial trade, futures markets, and by grain elevators nationwide. For standard-quality grain at normal moisture levels, the conversions produced by this calculator will be highly accurate.

However, there are several factors that can cause actual grain weights to differ from the standard:

• Moisture content: This is the most significant variable. Standard test weights assume grain at a specific moisture level (e.g., 15.5% for corn, 13.5% for wheat). Grain harvested at higher moisture will be heavier per bushel due to the water weight, but will yield fewer dry-matter bushels. Conversely, very dry grain may have a higher test weight than the standard.
• Test weight variation: Even at the same moisture content, test weight varies by variety, growing conditions, maturity at harvest, and storage conditions. A particularly good crop of corn might test at 58-60 lbs/bu rather than the standard 56 lbs/bu.
• Foreign material: Grain with excessive foreign material (broken kernels, weed seeds, dust) will have a different effective weight per bushel.
• Grain condition: Damaged, sprouted, or insect-infested grain will typically have lower test weights.

For most planning, estimating, and trading purposes, the standard weights used by this calculator are perfectly adequate. When precision is critical, such as at the point of sale at a grain elevator, the actual test weight of the specific grain lot should be measured and used for conversion.

How to Use This Calculator

Using the grain conversion calculator is simple and intuitive. Follow these steps:

1. Select your grain type from the dropdown menu. The calculator will automatically use the correct bushel weight for that grain. If your grain is not listed, select "Custom" and enter the weight in pounds per bushel manually.
2. Enter the quantity you want to convert in the "Input Value" field. You can enter any positive number, including decimals.
3. Choose the input unit from the "Input Unit" dropdown. This is the unit your quantity is currently expressed in (e.g., if you have 500 bushels, select "Bushels").
4. Choose the output unit from the "Output Unit" dropdown. This is the unit you want to convert to (e.g., if you want to know the equivalent in metric tonnes, select "Metric Tonnes").
5. Click the "Convert" button. The calculator will display the converted value prominently, along with a complete summary table showing the equivalent quantity in all available units.

For the grain bin capacity calculator, simply enter the diameter of your bin and the height of the grain, then click "Calculate Bin Capacity" to see the storage volume in bushels.

Frequently Asked Questions

How many pounds is a bushel of wheat?

A bushel of wheat weighs 60 pounds according to the USDA standard test weight. This is the weight used in all commercial grain trading in the United States. The same 60-pound standard applies to soybeans as well.

How many bushels per metric tonne of corn?

One metric tonne of corn equals approximately 39.37 bushels. This is calculated by converting 1 metric tonne to pounds (2,204.62 lbs) and dividing by the corn bushel weight of 56 lbs: 2,204.62 / 56 = 39.37 bushels.

How do you convert bushels to tonnes?

To convert bushels to metric tonnes, first multiply the number of bushels by the grain's standard weight per bushel to get pounds, then divide by 2,204.62 (the number of pounds in a metric tonne). For example, 1,000 bushels of wheat = 60,000 lbs / 2,204.62 = 27.22 metric tonnes.

How many bushels fit in a grain bin?

The number of bushels a grain bin holds depends on its diameter and the height of grain inside. Use the formula: Bushels = (pi x radius² x height) / 1.244. For example, an 18-foot diameter bin filled to 12 feet holds approximately 2,454 bushels. Use our grain bin capacity calculator above for quick results.

Why do different grains have different bushel weights?

Different grains have different bushel weights because they have different densities. A bushel is fundamentally a unit of volume (about 1.244 cubic feet), and denser grains weigh more per unit of volume. Wheat and soybeans are relatively dense at 60 lbs/bu, while oats are much lighter at 32 lbs/bu because oat kernels have a large, lightweight hull that takes up volume without adding much weight. The USDA established standard weights for each grain to ensure fair and consistent trade.

What is test weight?

Test weight is a measure of grain density, expressed in pounds per bushel. It is determined by weighing a known volume of grain (typically using a standardized test cup). Test weight indicates grain quality: higher test weight generally means plumper, more mature kernels with more starch and less moisture. Grain that meets or exceeds the USDA standard test weight (e.g., 56 lbs/bu for corn) is considered "No. 2" grade or better. Grain with lower test weight may be downgraded and receive a lower price. Test weight can be affected by growing conditions, harvest timing, moisture content, and storage practices.