Shrimp biomass & FCR estimator from daily feed
From the feed you log each day and the size from your cast-net sample, the estimator works out the kg of shrimp in the pond, the count, survival and running FCR. Pick the tab for your stage and fill in 2–3 cells to get results, with the working shown so you can explain it to farmers. Keep a pond log for charts, alerts and Excel export.
Shrimp in the nurseryAuto
Fill in total feed and sampled size in the yellow cells — results appear instantly.
What is the estimator based on?
- Grow-out: biomass = whole-day feed ÷ feed rate for the size; count = biomass × size (shrimp/kg). E.g. 50 kg ÷ 5.5% = 909.1 kg of shrimp × 100/kg ≈ 91,000 shrimp.
- Nursery: count = total feed since stocking ÷ feed mark per 100,000 shrimp × 100,000 (marks: 220 kg at 500/kg, 250 kg at 400/kg — reference marks, adjust them to your own pond).
- Transfer: actual shrimp weight = weighed kg × (1 − % water): plastic basket minus 20%, dip net minus 25%, drained shrimp: no deduction. Count = actual weight × sample count (shrimp/kg).
- Survival = estimated count ÷ number stocked. Running FCR = cumulative feed since stocking ÷ (estimated biomass − stocked weight); stocked weight = number stocked ÷ stocking size.
- No-feeding days (0 kg of feed — moulting, water treatment): biomass is not estimated that day, but the feed still counts towards the cumulative total.
| Shrimp size (/kg) | Feed rate (Southern Vietnam practice) | kg feed / 100 kg shrimp |
|---|---|---|
| 500 | 10% | 10 |
| 400 | 9% | 9 |
| 300 | 8.5% | 8.5 |
| 200 | 7.75% | 7.75 |
| 150 | 6.5% | 6.5 |
| 100 | 5.5% | 5.5 |
| 40 | 3.35% | 3.35 |
| 30 | 2.65% | 2.65 |
| 20 | 2.1% | 2.1 |
The feed table follows Southern Vietnam farm practice and is usually higher than feed brands' tables (e.g. at 100 shrimp/kg: 5.5% vs 3–4%), so the estimated count may be lower than reality. Always adjust feed by your feed trays. The table, nursery marks, % water and alert thresholds can all be edited in the “Feed table” tab and inside each tab.
When does the estimator warn you?
- Estimated survival above 100%: the feed table may be too low for this pond, or the size entered may be off — re-sample to check.
- Count drops more than 10% over 3 consecutive days with no change in size: shrimp may be declining — check the feed trays, the pond bottom, the gut and hepatopancreas.
- Running FCR rises more than 0.15 within 7 days: check whether you are overfeeding.
- More than 7 days without a sample: the old size makes results less accurate over time.
The pond log is stored on your phone only and never sent to a server. Technical support: +84 867 957 568.
Other tools:Shrimp feed calculatorNH₃ & NO₂ toxicity calculatorMineral calculator