How to use this calculator
- Enter or choose birds placed.
- Enter or choose birds found dead.
- Enter or choose birds culled.
- Enter or choose days since placement.
- The cumulative mortality updates as you type. Use Copy result or Share to keep it.
Method
Mortality % = (Dead + Culled) ÷ Placed × 100; Livability % = 100 − Mortality %; Daily % = Mortality % ÷ Days
- Placed
- birds at the start of the flock
- Dead, Culled
- cumulative losses to date
- Days
- days since placement
Worked example
- Losses = 150 + 50 = 200 birds.
- Mortality = 200 ÷ 5,000 = 4%; livability = 96%; 4,800 birds remain.
- Average per day = 4% ÷ 42 = 0.095%.
Losing 200 of 5,000 birds in 42 days is 4% cumulative mortality, about 0.095% a day.
What the result means
Mortality is rarely even: the first week and heat or disease events dominate. Record losses daily and look at weekly figures to spot problems early; a sudden rise warrants a vet’s attention.
Assumptions and limits
- Culls count as losses alongside deaths.
- The daily figure is an average and hides peaks.
- Birds moved out or sold early are not counted as losses; subtract them from birds placed if needed.
Questions
Should culls count as mortality?
Most flock records report total losses (dead plus culled) and also show each separately, as this calculator does.
What is a normal mortality rate?
It depends on the bird type, age, housing and region. Compare with your own records and with your breed company’s or integrator’s targets.