The formula for weighing a pig using a tape measure is: Heart Girth x Heart Girth x Length/400
Length is taken from between the ears to where the tail starts.
This method of weighing a Kunekune is not as accurate as it would be for a traditional hog. Kunekune have a higher percentage of fat, which is lighter than lean muscle. So a round Kunekune might appear to look heavier than they actually are. Consider this when determining the amount of medication you should give your pig.
I have a scale at our farm so I decided to compare the two methods. Here are the results.
Pig Scale Weight Formula Weight Measurements % of Formula Weight
#1 Gilt 172.5 194 43HG x 42L 88%
#2 Barrow 140 156 40HG x 39L 89%
#3 Sow 219.7 273.1 51HG x 42L 80%
#4 Sow 162.4 171 42HG x 39L 94%
#5 Boar 281 281 50HG x 45L 100%
#6 Boar 338 426 59HG x 49L 79%
As you can see from the data above, there is quite a bit of variation from one pig to the next. There was only one pig, Pig #5, that matched the Formula calculation. He was a large, young male with a large boned frame and less fat.
The biggest difference came from our largest male. He was a young boar with extreme length and width. Visually I would have thought he was closer to the Formula Weight. I was very surprised when I read his actual Scale Weight.
If you do not have a scale, using the formula will give you a basic idea of weight, but just keep in mind that the Kunekune is probably slightly lighter than the taped method.