Figuring out the age of a big fish you just caught can be a challenge. Northern pike are no exception in this matter. Though many anglers are surprised how quickly the fast-growing northern pike can reach legally catchable status.
At least in comparison to many other fish.
Northern pike grow fastest in the first two to three years of their lives reaching up to 25 inches and 2.5 lbs in that time. Males generally mature into adult fish in 2 years, females in three. After the first five years a very rough rule of thumb is approximately 1.3 lbs and 1.2 inches a year.
There are a variety of factors that can affect the rate of growth early in life of northern pike, as well as the maximum size that they reach. A northern pike in Iowa or Wisconsin, for example, will have very different ceilings on their size than one found in Ontario, Alaska, or Sweden.
| Age (years) | Avg Male Length (In) | Avg Male Weight (lbs) | Avg Female Length (In) | Avg Female Weight (lbs) |
|---|---|---|---|---|
| 1 | 10 | .5 | 13 | .75 |
| 2 | 12.5 | .75 | 15 | 1.2 |
| 3 | 19 | 1.5 | 22 | 2.2 |
| 5 | 25.5 | 2.3 | 27 | 3 |
| 7 | 28 | 3.1 | 30 | 4 |
| 10 | 31 | 4 | 33 | 8 |
| 15 | 36 | 11 | 38 | 15 |
| 20 | 40 | 21 | 42 | 24 |
| 25 | 46* | 30* | 47 | 33 |
| 30 | N/A | N/A | 49 | 40 |
That table is a basic guideline. The asterisk (*) denotes the fact that very, very, VERY few male pike make it to this age. Even in ideal circumstances
There are going to be changes based on a variety of local factors. A couple more example of some rough northern pike growth charts or estimates can be found here:
- Great growth chart estimate from Wilderness North
- Rough estimate from Wisconsin DNR
- Outdoor Canada comparing pike growth rates in two lakes
Not every growth chart is going to be accurate for every area. An excess or shortage of food can speed up, or stunt, growth rates respectively. An overpopulation of pike in an area can also affect things.
It’s also worth noting that climate plays a big part in how quickly pike grow as extreme northern climates give a trade off of bigger old fish that live longer at the price of taking longer to grow to that size.
Growth Factors for Northern Pike
There tends to be a standard growth rate for pike, and in some places they grow a little bit slower, in others a bit faster. That’s how averages work, and while pike are a sturdy fish that thrives in virtually any northern freshwater environment, there are still many factors at play for determining northern pike growth rates.
If you’re an angler chasing some huge northern pike knowing these factors can make all the difference!
Sex of the Fish
When it comes to many types of fish, but especially northern pike, female fish grow much larger than males. For example, the ceiling for most male pike is right around 30 lbs. And those guys are the great grandfathers of pike.
Unless it’s a real outlier or “genetic freak,” every pike that size or larger are going to be female.
Females grow faster and get bigger. After a certain size (generally 46 in. and 25 lbs) the fish is going to be female. Even the lengths and pounds leading up to that level have 97/3, 98/2, or even 99/1 female to male pike ratios.
Females continue to grow at a steady pace, many times for decades after the oldest males tend to die off. This is why growth rates for large pike slow down, and also in part why they are so hard to find.
Not to mention the fact that a 40 lb female has to eat plenty to keep enough energy for a fish body that size.
Geography
A general rule of thumb is that the further south northern pike are in their natural habitat, the faster they grow in early years. This comes at a price of shorter lifespans. This is why you don’t find 30 lb pike in places like Iowa or Illinois.
The colder the environment (up to a point), the slower pike will grow. However, they will also live longer and thus grow to bigger total sizes.
The average temperatures and seasonal lengths in those areas also make a difference when it comes to how quickly the fish grow. So that needs to be a consideration.
While the charts in these articles are great averages, if a long-time local guide swears up and down by a different growth chart then trust the local chart from the experienced local guides.
Environment
Are there plenty of spawning areas? Plenty of food? Enough space to really grow? Things that affect prey fish populations can, in turn, have a major effect on pike growth rates, as well.
Pike are ambush predators, so having an environment that lets them use their unique skills and hunting abilities to get plenty of food for less effort makes all the difference.
Food Sources
How much food is available? Is there enough to support a lot of large pike or just a couple? Is there a lot of fair sized food or just minnows and very small fish?
These food questions can absolutely affect the rate of growth of any northern pike in an area.
Pike Fishing Regulations in the Area
In areas where pike are considred an invasive species you won’t see nearly as many big ones as anglers will go to town on them. If the catch and release is very strict, then you will have more large, old fish.
The only predator that adult northern pike have are either bigger pike, and then at a certain size only people. If anglers aren’t allowed to keep them, then the pike can grow bigger and age longer for more trophy-sized fish.
In Conclusion
Who doesn’t love the fight that a northern pike can bring to the table? By understanding their average growth rates you actually can have an idea of just how old that pike you caught is.
Gives you a new found respect for these amazing fish and what they went through to grow to that size before your master angler skills finally brought them into the boat!