Grain Storage Capacity Calculator & Tonnes & Bags a Bin Holds
Sizes storage for wheat
Find how many tonnes and bags a bin, silo or godown holds — from its dimensions and the grain's bulk density — for box or cylindrical stores, at any fill level.
Wheat: bulk density ≈ 0.78 t/m³.
This bin (12 m³) filled to 90% holds about 8.42 tonnes of wheat — roughly 168 bags of 50 kg. Grain capacity depends on bulk density, so the same bin holds more dense rice than light barley.
Next: dry grain to safe storage moisture first, leave headspace for aeration, and keep stores dry, rodent-proof and ventilated. Don't fill to the brim if you need to turn or treat the grain.
Bulk densities are typical test weights; actual capacity varies with moisture, variety and settling/compaction.
Grain storage — key facts
- Box volume
- L × W × H
- Cylinder volume
- π × radius² × height
- Tonnes
- volume × fill × bulk density
- Wheat
- ≈ 0.78 t/m³
- Paddy / rice
- 0.58 / 0.85 t/m³
- 1 t wheat needs
- ≈ 1.28 m³
- Realistic fill
- 85–90%
- Privacy
- Runs in your browser; nothing uploaded
Know your store before harvest comes in
Capacity is volume times density: a bin's cubic metres multiplied by the grain's bulk density gives the tonnes it will hold. Because grains differ — milled rice is half as bulky again as paddy — the same bin holds very different tonnages depending on what goes in it. This tool computes the volume of a box or cylindrical store, applies your fill level, and converts to tonnes and bags using tested bulk densities, so you can match storage to the harvest you expect.
Plan with a realistic fill — leave headspace for loading and aeration, since heaped grain never fills the top corners — and always dry the crop to safe storage moisture first, or it heats, moulds and is downgraded. Use the tonnage to decide whether your existing store is enough or how big a new bin to build, and pair this with the Crop Yield Estimator to check your store will hold what the field produces.
Size a store
Work out the tonnes and bags a bin, silo or godown will hold before you build or buy.
Match grain to space
See how capacity changes with the grain, since denser grain packs more tonnage.
Plan the harvest
Check your storage can take the expected yield, or how much extra you need.
Box or silo
Works for rectangular godowns and cylindrical metal bins alike.
Frequently Asked Questions
How do I calculate grain storage capacity?+
Work out the bin's volume (length × width × height for a box, or π × radius² × height for a cylinder), multiply by the fill level, then by the grain's bulk density (tonnes per m³). A 3 × 2 × 2 m bin full of wheat (0.78 t/m³) holds about 9.4 tonnes. This tool does it for any size and grain.
What is grain bulk density?+
Bulk density (or test weight) is the mass of loose grain per unit volume — wheat ≈ 0.78, milled rice ≈ 0.85, paddy ≈ 0.58, maize ≈ 0.72 tonnes per cubic metre. Denser grain packs more tonnage into the same bin, which is why capacity depends on the grain, not just the size.
How many bags will my bin hold?+
Divide the tonnage by your bag weight: a bin holding 9.4 tonnes of wheat stores about 188 bags of 50 kg. The tool reports both tonnes and bags for the bag size you set.
How do I find the volume of a cylindrical silo?+
Volume = π × radius² × height, where radius is half the diameter. A silo 2 m across and 3 m tall has a volume of about 9.4 m³. Switch the tool to cylinder mode and enter the diameter and height.
Why shouldn't I fill a bin to 100%?+
Leave headspace for loading, aeration and turning the grain, and because grain heaped at its angle of repose doesn't fill the very top corners evenly. A fill level of 85–90% is realistic for usable capacity; set the fill % to match.
Does moisture affect storage capacity?+
Slightly — wetter grain is a little denser and heavier, but more importantly it must be dried to safe storage moisture first or it heats and moulds. Use the bulk density for dry, storable grain, and dry the crop before storing.
How much space does a tonne of grain need?+
Roughly the inverse of bulk density: a tonne of wheat (0.78 t/m³) needs about 1.28 m³, paddy about 1.7 m³, milled rice about 1.18 m³. Lighter grains need more space per tonne, so plan bin size around the grain you'll store.
Can I use this for a warehouse or godown?+
Yes — use box mode with the floor length and width and the height to which grain will be stacked or heaped. For bagged storage, the calculator's tonnage and bag count help you check the floor and stack will hold your harvest.
What's a safe way to store grain?+
Dry to safe storage moisture, clean and disinfest the store, keep it dry and rodent-proof, stack bags on pallets off the floor with air gaps, and aerate or turn bulk grain to prevent hot spots. Monitor for moisture and pests through the season.
Are the bulk densities exact for my grain?+
They're typical test weights and vary with variety, moisture and how tightly the grain settles. For precise stock-taking, weigh a known volume of your own grain to get its actual bulk density, then re-enter it via a custom grain figure.