Stock Unit Calculator NZ 2026
This calculator converts head of stock into stock units, the standard measure of feed demand on a New Zealand pastoral farm, and returns your total stock units, your stocking rate per hectare and the dry matter that many stock units will eat in a year. A stock unit is the annual feed demand of one 55 kilogram breeding ewe rearing a single lamb, so a farm running sheep, cattle and deer together can be described in a single number that farmers, valuers, banks, councils and real estate agents all understand. The thing this page does differently is worth explaining before you use it. There is no official New Zealand stock unit table. Published sources genuinely disagree, and not by trivial amounts: one table puts a hogget at 1.0 and another at 0.7, one puts a dairy cow at 6.8 and another somewhere between 7 and 8.5. Those differences reflect real variation in liveweight, production and farm system, and on a decent sized farm they can move the total by several hundred stock units. So this calculator makes you choose which table to use, shows you both, and lets you edit any individual factor to match your own stock. If you are preparing a figure for someone else, ask which table they work from before you send it. If it is for your own planning, being consistent from year to year matters more than which table you picked.
| Class of stock | Head | Stock units each | Stock units |
|---|---|---|---|
| Breeding ewes | 200.0 | ||
| Hoggets | 50.0 | ||
| Rams | 2.4 | ||
| Beef cows | 66.0 | ||
| Dairy cows | 0.0 | ||
| Red deer hinds | 0.0 | ||
| Dairy goats | 0.0 |
The two published tables give 318.4 and 319.9 stock units for this stock, a difference of 1.5. Ask which table your bank, valuer or council works from before sending them a figure.
How it works
Each class contributes its head count multiplied by its stock unit factor, and the total is the sum. Choosing a table fills the factor column, and every factor stays editable so you can match your own stock: a big Angus cow and a small Hereford cow are not the same animal, and neither is a well grown hogget and a light one. The stocking rate divides total stock units by your effective grazing area, which should be the area actually grazed rather than the title area, so take out the bush, the races, the yards and anything else stock never eat off. Annual feed demand multiplies stock units by the dry matter figure you choose. Both 520 and 550 kilograms a year are in common use, which is another small disagreement worth knowing about, and the difference across a whole farm is not nothing.
Worked example
A hill country block runs 200 breeding ewes, 50 hoggets, 3 rams and 15 beef cows over 120 effective hectares. On the RuralFind table that is 200 stock units of ewes, 50 of hoggets, 2.4 of rams and 66 of beef cows, giving 318.4 stock units from 268 head, or 2.65 stock units per hectare. At 550 kilograms of dry matter a stock unit, those animals will eat about 175,120 kilograms of dry matter over a year. The same stock on the conventional consultant table comes to 319.9, because that table rates hoggets lower at 0.7, which takes 15 stock units off, but beef cows higher at 5.5, which puts 16.5 back on. The two differences nearly cancel here by luck. That will not always happen: swap the beef cows for dairy cows and the tables diverge sharply.
Related calculators
- Lifestyle Block Stocking: how many animals a small block will carry.
- Winter Hay and Baleage: turning feed demand into bales.
- Stock Water Requirements: what that stock drinks.
- Acreage: working out your effective area.