Calculate a daily fish-feed ration, feed per meal, feed coverage, and a reorder point based on your supplier lead time.
Table of contents
How to use our Aquaculture Daily Feed Ration, Inventory and Reorder Calculator
- Choose how you know current fish weight and select the matching feed and biomass unit.
- Enter "Standing biomass", or select "Fish count basis" and enter the matching count plus "Average fish weight". "Current live fish count" uses the count directly. "Originally stocked count with remaining percentage" also uses "Estimated remaining fish (percent)".
- Enter the planned Feed rate and Meals per day. Replace the 2 percent example with the rate in your current feeding plan.
- Choose whether feed inventory is counted by weight or bags, then enter the visible inventory fields plus Supplier lead time and Safety buffer.
- Check that Biomass used for ration matches recent sampling records, then use Feed order decision and Days until reorder point to plan the order.
Definitions
Standing biomass: Total current live fish weight. It is entered in pounds or kilograms and is the direct starting point for the ration.
Estimated remaining fish (percent): The percentage of originally stocked fish still present and alive. This adjustment applies only to the originally stocked count; a current live count is not reduced again.
Feed rate: Feed as a percent of fish body weight per day. A rate of 2 means 2 percent of the calculated biomass each day.
Feed on-hand coverage: The number of days current usable feed should last at the planned daily ration.
Feed reorder point: The amount of feed needed to cover supplier lead time plus the chosen safety buffer.
Days until reorder point: Feed coverage remaining after subtracting supplier lead time and safety buffer. A negative value means the reorder point has already been reached.
Common mistakes and quick fixes
Mistake: Entering a feed rate for each meal in Feed rate.
Fix: Enter the percent of body weight fed over the whole day. Meals per day only splits that daily amount.
Mistake: Using both Standing biomass and fish-count details as if they are added together.
Fix: Choose one route under How do you know current fish weight?. The calculator uses only the active route.
Mistake: Reducing a current live count for mortality a second time. Fix: Choose "Current live fish count" for an updated count. If using the original stocking number, choose "Originally stocked count with remaining percentage" and include deaths and removals in the remaining percentage.
Mistake: Entering a bag count as Feed on hand.
Fix: Choose Bags under How is feed on hand counted?, then enter Feed bags on hand and the labeled Weight of one bag.
Mistake: Treating Supplier lead time as the same thing as Safety buffer.
Fix: Use lead time for expected delivery days and buffer for the extra days of cover your farm chooses.
Limitations & Key Assumptions / Boundary Conditions
- The daily ration is a planning amount based on entered biomass and feed rate. Fish appetite, water conditions, health, size variation, and feeding response can require changes.
- The fish-count route estimates biomass from an average sample weight and either a current live count or an adjusted original count. Old or unrepresentative samples can make the ration inaccurate.
- The calculator splits the daily ration equally across Meals per day. It does not adjust individual meals for observed feeding behavior.
- Feed on-hand coverage assumes all counted feed is usable and that the daily ration stays constant.
- The reorder decision assumes delivery takes the entered Supplier lead time. Delays, partial deliveries, and feed use changes can require ordering earlier.
- A zero Feed on hand value is allowed and produces an immediate order decision. This calculator requires a feed rate greater than zero to estimate ration and inventory coverage. For an intentional no-feeding day, no ration is needed; coverage from that zero rate is undefined.
Methodology
Calculation method
The calculator uses one biomass route at a time. The direct route uses standing biomass. A current live count is multiplied directly by average fish weight; an originally stocked count is first multiplied by the estimated remaining percentage. Average weight uses ounces with pounds or grams with kilograms.
daily feed ration = biomass used for ration x feed rate / 100
current-count biomass = current live fish count x average fish weight; stocked-count biomass = originally stocked count x estimated remaining percent / 100 x average fish weight
For the fish-count route, the average fish weight is converted to the selected biomass unit before the biomass calculation. The calculator uses 16 ounces per pound, 1,000 grams per kilogram, and 2.2046226218 pounds per kilogram.
feed on hand = direct feed weight OR feed bags on hand x weight of one bag
feed reorder point = daily feed ration x (supplier lead time + safety buffer)
feed on-hand coverage = feed on hand / daily feed ration
days until reorder point = feed on-hand coverage - supplier lead time - safety buffer
feed per meal = daily feed ration / meals per day
Worked example
With 1,000 lb of biomass, a 2 percent daily feed rate, and 2 meals per day, the daily feed ration is 20 lb/day and feed per meal is 10 lb/meal. If 200 lb is on hand, supplier lead time is 5 days, and the safety buffer is 2 days, the reorder point is 140 lb. Feed covers 10 days, so the reorder point is 3 days away.