Free farm tool
Grain Store Capacity Calculator
Enter the bay's dimensions and the crop - get an estimate of how many tonnes fit, using typical bulk densities.
Grain volume
720 m³
Estimated tonnes of wheat
551 t
24 m × 12 m × 2.5 m average depth at ~0.765t/m³. Use the average depth across the heap, not the peak - a heaped pile's average is usually well under half its highest point plus wall height.
The arithmetic
Tonnes = length × width × average depth × bulk density. The first three give you cubic metres of grain; the density converts volume to weight. The number that catches people out is average depth - grain heaps at an angle of repose around 25–28°, so a pile peaking at 4m against the back wall might average barely 1.8m across the floor.
Bulk densities to use
| Crop | Bulk density (t/m³) | Tonnes per m² per metre of depth |
|---|---|---|
| Wheat | 0.75–0.78 | ~0.76 |
| Barley | 0.62–0.70 | ~0.66 |
| Oilseed rape | 0.65–0.68 | ~0.66 |
| Oats | 0.50–0.55 | ~0.52 |
| Beans | 0.80–0.83 | ~0.81 |
Note the practical consequence: the same bay holds roughly a third less oats than wheat by weight. If you grow both, shed allocation done in “tonnes of space” without the density correction will run out of room.
Estimates plan; weights settle
This calculator is for planning - will this year's wheat fit, how to split the sheds before the first trailer tips. Once harvest runs, the honest answer to “what's in shed 2?” is the sum of weighed loads in minus loads out, recorded as they happen. Our guides on working out what fits in a shed and weighing grain without a weighbridge cover both halves of that.
Frequently asked questions
How do you calculate grain store capacity?
Multiply floor length by width by the average grain depth to get volume in cubic metres, then multiply by the crop's bulk density. A 24m × 12m bay filled level to 2.5m holds 720 m³ - about 550 tonnes of wheat at 0.765 t/m³.
What is the bulk density of wheat?
Stored wheat typically runs 0.75–0.78 tonnes per cubic metre. Barley is lighter at 0.62–0.70, oilseed rape around 0.65–0.68, oats 0.50–0.55, and beans heavier at 0.80–0.83. Actual density varies with variety, moisture, and how much the heap has settled.
How accurate are heap estimates?
Estimating a heap by eye is commonly out by 10% or more - that's an 80-tonne error on an 800-tonne shed. The geometry misleads: a heaped pile's average depth is much less than its peak suggests. This calculator narrows the guess; weighed loads in and out are the only accurate running total.
How many tonnes of wheat fit in a shed per square metre?
Roughly 0.76 tonnes per square metre for every metre of average grain depth. So a level fill 3m deep holds about 2.3 t/m² of floor - 275 tonnes in a 10m × 12m bay.
Weighing loads this harvest? Stop adding them up by hand.
Harvestt records every weighbridge load against crop, field, and shed - and does this arithmetic for you, live.
Try Harvestt