Grain Bin Calculator
Grain bin bushels, tons, and truckloads from bin dimensions.
What it does
Grain bins hide volume in cylinders. Diameter and fill height turn into bushels, tons, and truckloads fast.
The tool above runs the cylinder. Eighteen by twenty feet holds 4072 bushels weighing 114 tons across 4.1 truckloads. The metric match is 5.5 by 6.1 m for 4116 bushels.
Eight tenths bushels per cubic foot suits shelled corn. Small grains pack denser, ear corn lighter.
Tons follow at fifty six pounds per corn bushel. Moisture discounts dock light grain at the elevator.
Trucks close harvest. Thousand bushel semis pace hauling against bin space.
How to use
- Pick imperial (ft) or metric (m).
- Enter bin diameter and grain height.
- Read bushels first.
- Read tons next.
- Read truckloads and book hauls.
Formula
- D
- Bin diameter.
- H
- Grain height.
Metric runs 28.4 bushels per m3 with 0.0254 tonnes per bushel. Trucks assume 1000 bushels each.
Worked example
Example: 18 by 20 ft bin
Imperial defaults: 18 ft by 20 ft bin. These are also the default values, so the page opens on this answer.
- Bin: 18 ft across, 20 ft tall.
- Volume: 3.1416 x 18 x 18 / 4 x 20 = 5090 ft3 after rounding (5089.4).
- Bushels: 5090 x 0.8 = 4072 bushels.
- Tons: 4072 x 56 / 2000 = 114 tons.
- Trucks: 4072 / 1000 = 4.1 truckloads.
- Tool shows 4072 bushels, 114 tons, 4.1 truckloads.
Reference table
| Bin | Bushels | Tons |
|---|---|---|
| 12 by 15 ft | 1357 bushels | 38 tons |
| 18 by 20 ft | 4072 bushels | 114 tons |
Limits
- Volume math only. Moisture docks apply.
- Cone bottoms need geometry tweaks.
- Aeration needs management.
- Bin ratings gate fills.
Common mistakes
- Gross volume with no fill factor.
- Ignoring moisture dockage.
- Overfilling past roof vents.
- No aeration in warm grain.
- Booking trucks before testing.
Try it yourself
Quick checks. Answers sit tucked under each question.
12 by 15 ft bin?
Volume is 3.1416 x 12 x 12 / 4 x 15 = 1696 ft3 after rounding (1696.5). Bushels are 1696 x 0.8 = 1357 bushels after rounding (1356.8).
10 by 10 ft bin?
Volume is 3.1416 x 10 x 10 / 4 x 10 = 785 ft3 after rounding (785.4). Bushels are 785 x 0.8 = 628 bushels.
Questions
Bushels in the bin?
Multiply cylinder volume by 0.8. Here 5090 x 0.8 = 4072 bushels.
Bushels per foot?
Near 0.8 bushels per cubic foot for shelled corn in this plan.
Tons of corn?
Multiply bushels by 56 lb over 2000. Here 4072 x 56 / 2000 = 114 tons.
Truckloads?
Divide bushels by 1000. Here 4.1 truckloads.
Moisture matter?
Yes. Moisture discounts dock light grain.
Storage management?
No. Aeration and cables need storage plans.