Grain Bin Calculator

The grain bin calculator can estimate the contents or capacity of a grain bin. You can use the tool as a grain bin bushel calculator to conveniently determine the number of bushels you can store for your farming operation’s dry storage, or the volume and product weight. In this article, you'll learn how to calculate grain bin capacity and why grain bins get designed the way they are.

Grain bins or grain silo towers are vast galvanized metal tins used to store harvested grains such as soybeans, corn, and wheat. It protects your months of hard work and harvests from rodents, weather, and other destructive elements.

Most metal grain bins come in circular or cylindrical shapes, but different shapes (e.g., square and rectangular flat storage) are readily available for farm producers interested in custom designs. The round shapes are popular because they are easier to clean compared to shapes with corners.

Another common feature of grain bin designs is a piled or conical top and, sometimes, a hopper bottom. These top-fills allow the grain bin to be quickly loaded with grains through a central hatch, while the hopper bottom allows the grain bin's content to be easily emptied thanks to gravity.

The structure also ensures proper ventilation and movement of air current through the metal grain bins. Flat bottom rectangular grain bins are also common. They are easier and cheaper to construct with a concrete foundation that makes them suited for holding grains indefinitely.

Just like shapes, the sizes also vary if you're considering grain bins for sale. Some metal grain bins can hold 1,000 bushels (about 25.4 metric tons) of grain, while others can hold up to 1 million bushels.

The grain bin capacity calculator allows you to calculate the volume and bushels of grain in these large grain silos. You can determine the grain bin capacity by inputting the grain bin dimensions or use the tool as a grain bin size calculator when you provide the capacity you're looking to get.

Suppose you are developing a custom grain storage plan for your farm operation. In that case, you can use the grain bin bushel calculator during your initial site analysis and make estimates for the storage requirements.

Follow these steps in no particular order to get the grain bin capacity and product of a grain bin:

1. Select the grain bin type, round or rectangular.
2. Indicate if the grain bin has a roof by selecting the shape/type of roof. Fill in the roof's height.
3. Indicate if the grain bin has a hopper. Fill in the hopper's height.
4. Provide the dimensions of the grain bin — height, Width, Length, and Diameter. The Radius of the grain is half of the grain bin diameter, which is provided in the manufacturer's information.
5. If you want to find the total grain weight in the grain bin, all you need to do is provide the test grain weight.

You can use the grain bin calculator whether the grain bin gets partially filled or you want to know how much capacity is remaining.

The formulae to calculate the grain bin capacity for different grain bin shapes are as follows:

• Round grain bin capacity (bushels) = $\small πR^2 \cdot H \cdot \text{conversion constant}$

  When the grain bin body has top fill and hopper;

  Round grain bin with peaked top and hopper (bushels) = $\small πR^2\cdot H \cdot \text{conversion constant} + \frac{1}{3}πR^2\cdot H_2 \cdot \text{conversion constant}+ \frac{1}{3}πR^2\cdot H_3 \cdot \text{conversion constant}$

  Round grain bin with curved top and hopper (bushels) = $\small πR^2 \cdot H \cdot \text{conversion constant} + πR^2\cdot (\frac{2}{3}R+H_2) \cdot \text{conversion constant}+ \frac{1}{3}πR^2\cdot (\frac{2}{3}R+H_3) \cdot \text{conversion constant}$

• Rectangle grain bin capacity (bushels) = $\small L \cdot W \cdot H \cdot \text{conversion constant}$

  When the grain bin body has a top fill:

  Rectangle grain bin with peaked top (bushels) = $\small L \cdot W \cdot H \cdot \text{conversion constant} + \frac{1}{3}L \cdot W \cdot H_2 \cdot \text{conversion constant}$

  Rectangle grain bin with curved top (bushels) = $\small L \cdot W \cdot H \cdot \text{conversion constant} + L \cdot W \cdot(\frac{2}{3}+ H_2)\cdot \text{conversion constant}$

  where:

  • $R$ — Radius of the grain bin, which equals its diameter divided by 2;
  • $H$ — Peak height of the grain bin, where:
    • $H_1$ — Body height of the grain bin;
    • $H_2$ — Height of top fill if the grain bin has a piled or conical fill; and
    • $H_3$ — Height of the bottom fill if the grain bin has a hopper.
  • $L$ — Body length of the grain bin;
  • $W$ — Width of the grain bin; and
  • $\text{conversion constant}$ — 0.7786 bushels per cubic feet.

Disclaimer:

• All dimensions have to be in the same units when using the formulae. When doing your calculations, you can use our length converter. With the grain bin calculator, you can switch between imperial and metric measures to get your results irrespective of units.
• The grain bin calculator results are estimated values based on the figures you provide. Estimates provided when a grain bin has a roof and/or hopper do not account for the variability in the angle of repose as the grains are filled or piled.

Before you go, check out our corn yield calculator.