Feed Conversion Calculator

Turn feed logs into clear performance metrics fast. Model waste, stocking, harvest, and growth easily. Plan smarter rations for healthier yields across seasons always.

Inputs
Responsive 3–2–1 column form

Use this for backyard fish ponds, poultry feed logs, rabbits, or any small growing system where feed and biomass are tracked.

Keep the same unit for all weights.
Total feed given during the period.
Estimate uneaten/lost feed; default 5%.
Starting total live weight.
Ending total live weight.
New animals/fish added during the period.
Harvest/sales/removals during the period.
Used for daily gain and daily feed.
Optional label for your records.
Add a batch name, pen ID, or pond label.
Reset
Example Data Table

Sample records to understand typical inputs and results.

System Feed Offered Initial Biomass Final Biomass Removed Waste FCR
Backyard tilapia pond 25 kg 80 kg 100 kg 0 kg 5% 1.1875
Layer hens batch 18 kg 45 kg 52 kg 0 kg 3% 2.4943
Rabbits, partial sale 12 kg 20 kg 24 kg 2 kg 4% 2.3040
Formula Used
  • Effective feed consumed = Feed offered × (1 − Waste% ÷ 100)
  • Net biomass gain = (Final biomass + Removed biomass) − (Initial biomass + Added biomass)
  • Feed conversion ratio (FCR) = Effective feed consumed ÷ Net biomass gain
  • Feed efficiency ≈ 100 ÷ FCR

Lower FCR usually means more growth per unit of feed. Compare runs only when units, species, temperature, and stocking conditions are similar.

How to Use This Calculator
  1. Pick a unit and keep it consistent for the period.
  2. Enter total feed offered and an estimated waste factor.
  3. Enter starting and ending biomass from weighings or counts.
  4. Add biomass stocked, and biomass removed or harvested.
  5. Set the number of days to see daily rates.
  6. Press Calculate to view results above the form.

Use the download buttons after calculation to save reports. Keep raw feed logs and weighing notes so you can audit improvements.

Why feed conversion matters in garden systems

Feed conversion ratio links what you offer to the growth you actually produce. In backyard ponds, coops, and hutches, feed is usually the largest variable cost. Tracking FCR helps you spot overfeeding, disease stress, poor water quality, or low-energy rations before losses become visible. It also supports budgeting and stocking plans when space is limited.

Define consistent measurement boundaries

Use one unit for the entire period and record the same group each time. Weigh biomass at the start and end, then note any stocking or harvest events. The calculator uses a simple mass balance, so missing additions or removals will distort gain and inflate the ratio. If you estimate biomass by counts, keep the same average weight method.

Account for waste and handling losses

Uneaten pellets, spilled mash, and wind-blown feed can be significant in open garden setups. Apply a waste percentage that matches your management style and container type. Reducing waste by better feeders, shade, or split rations often improves effective feed more than changing diets. Watch for fines, mold, and moisture that reduce intake.

Interpret results with practical benchmarks

Lower FCR indicates better conversion, but compare only similar conditions. Temperature, stocking density, genetics, and moisture content can shift outcomes. Use the daily feed and daily gain outputs to check whether performance aligns with your growth targets for the season and space constraints. Sudden swings usually indicate measurement errors or a management change.

Use reports to drive improvement cycles

Run the calculator for each batch or month and download the report to build a history. When FCR rises, review water parameters, forage availability, and feeding schedule. When it falls, document what changed so you can repeat the practice across future cycles. Pair results with notes on weather, ration protein, and mortality for better decisions. Over time, these records let you compare feeds, adjust stocking density, and schedule harvest windows, improving output per square meter without adding labor or increasing water use significantly.

FAQs

What is a good FCR for small garden systems?

Good ranges depend on species and conditions. Use your own baseline first. Improving feeder control, water quality, and ration freshness typically lowers FCR more reliably than chasing a single universal target.

Why does the calculator include added and removed biomass?

Stocking and harvest change the group’s total weight. Including them keeps the gain calculation fair, so the ratio reflects feeding performance rather than mid-period transfers.

Should I use wet weight or dry weight for biomass?

Use whichever you can measure consistently, but keep it the same for all entries. Changing moisture assumptions between start and end can create false gains or losses.

How do I estimate waste percentage accurately?

Start with observation. Check leftover feed after a fixed time, inspect feeders for spills, and adjust the waste factor gradually. Consistent management practices make the estimate more stable.

Can I use this for compost worms or insect larvae?

Yes, if you can track feed input and biomass change. For very small batches, measurement error can dominate, so use longer periods and average multiple runs.

Why do my results look unrealistic after calculation?

Most issues come from missing removals, mixing units, or entering starting biomass higher than the adjusted ending biomass. Recheck each input, then rerun and compare against your notes.

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Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.

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