Storage Loss Calculator & What Spoilage Costs You
Counts losses in grain
See what storage really costs you — from quantity, monthly loss rate and period get the grain lost, the value lost, and how much better storage would save.
Enter your stored grain
Next: dry grain to a safe moisture (≈12–13 % for cereals) before storing, use airtight / hermetic storage (sealed bins or PICS bags), and treat & monitor regularly for insects, moulds and rodents.
Loss compounds: remaining = qty × (1 − rate)^months. Estimates only — actual losses vary with moisture, pests & temperature.
Storage loss — key facts
- Remaining
- qty × (1−rate)^months
- Well stored
- < 1%/month
- Poor storage
- 2–5%/month
- Main causes
- insects, moisture, rodents
- Best fix
- dry + airtight storage
- Paddy safe moisture
- ≈ 14%
- Loss compounds
- accelerates over time
- Privacy
- Runs in your browser; nothing uploaded
The harvest you lose after harvest
Growing the crop is only half the battle — a surprising share is lost after harvest, eaten by insects and rodents, spoiled by moisture and mould, or downgraded in quality while it sits in store. Because these losses compound month on month, grain held too long in poor conditions can lose 10–20% or more of its value, quietly erasing the profit you worked all season for.
This tool puts a number on it: the grain lost, the percentage and the money lost for your quantity, loss rate and storage period — and how much an improved storage method (lower loss rate) would save. Dry to safe moisture first, seal or treat the store, and weigh storing-for-a-better-price against the loss it costs. Pair it with the Crop Drying Time and Grain Storage Capacity tools to store smarter.
See the real cost
Put a money figure on grain quietly lost in store.
Justify better storage
Compare your loss rate to airtight/treated storage savings.
Time your sale
Weigh storing for a higher price against the loss it costs.
Target the worst
High loss % flags stores that need drying, sealing or treatment.
Frequently Asked Questions
How is storage loss calculated?+
Losses compound month on month, so remaining grain = quantity × (1 − monthly loss rate)^months, and loss = quantity − remaining. For 10 tonnes at 2% per month over 6 months, about 1.14 tonnes (11.4%) is lost. This tool computes the quantity lost, the percentage and the value.
What causes grain to be lost in storage?+
Mainly insects (weevils, borers), moulds and moisture, rodents and birds, plus spillage and quality downgrade. Warm, humid, poorly-sealed stores lose the most. Drying grain to safe moisture and using sealed or treated storage dramatically cuts these losses.
What is a typical monthly storage loss?+
It varies widely — well-managed storage may lose under 1% per month, while poor traditional storage in warm climates can lose 2–5% per month, especially from insects. Over a season these add up to large totals; post-harvest losses of 10–20% are common where storage is poor.
How much can better storage save?+
A lot. Dropping the monthly loss from, say, 2% to 0.5% can cut total losses by three-quarters over a few months. The tool compares your current rate against an improved rate and shows the grain and money saved — usually far more than the cost of better storage.
What is hermetic (airtight) storage?+
Sealed storage — airtight bags (e.g. GrainPro/PICS), drums or silos — that cuts off oxygen so insects suffocate and moulds can't grow, without chemicals. It's one of the most effective low-cost ways to slash insect losses in stored grain, often reducing monthly loss to near zero.
Does moisture affect storage loss?+
Critically. Grain stored above its safe moisture (about 14% for paddy, 12% for wheat) moulds, heats and attracts insects, accelerating loss. Drying to safe moisture before storage is the single most important step — pair this with a drying calculator to get there first.
Should I sell now or store and sell later?+
Compare the expected price rise against the storage loss plus storage cost and interest. If grain loses 11% over six months but the price only rises 8%, storing loses money. The tool's value-lost figure helps you weigh holding against selling at harvest.
How do I reduce insect losses?+
Dry grain well, clean and seal the store, use airtight storage or approved fumigation/inert dusts, store in a cool place, and inspect regularly. Remove infested grain promptly. Good hygiene before filling the store prevents carry-over infestation from last season.
Are quality losses included?+
This tool models weight loss from a monthly loss rate. Quality downgrade (discolouration, broken grains, off-odour) is an additional economic loss not captured in weight — so real financial losses from poor storage are often higher than the weight figure alone suggests.
How does loss compound over time?+
Each month's loss applies to what's left, so losses accelerate the longer grain sits — which is why long storage in poor conditions is so costly. The tool uses compounding (not simple addition) to reflect this, and shows the cumulative percentage for your storage period.