How much does a largemouth bass weigh?
Upload a photo of your catch, or use the tools below, to estimate its weight.
About the largemouth bass
Typical adult length: 10–20 in (about 0.8–6.7 lb)
- Lifespan
- Typically lives 10 to 16 years, with some individuals reaching 20.
- Habitat
- Favors warm, weedy lakes, ponds, and slow river backwaters with plenty of cover.
- Diet
- An opportunistic predator that eats smaller fish, crawfish, frogs, and large insects.
- Baits & techniques
- Plastic worms, jigs, spinnerbaits, and topwater lures fished around cover all work well.
- Best season
- Spring, around the spawn, and fall are generally the most productive seasons.
- Best time of day
- Early morning and late evening tend to produce the most bites.
- It's the most popular freshwater gamefish in North America.
- Largemouth bass can strike prey from above, below, or the side thanks to their large, upturned mouth.
- They build and guard nests, with the male fanning silt away and defending the eggs and fry.
Largemouth Bass length-to-weight chart
10 inches up to record size (30 in), using the standard length-to-weight formula for this species.
| Length (in) | Estimated weight (lb) |
|---|---|
| 10 | 0.8 |
| 12 | 1.4 |
| 14 | 2.3 |
| 16 | 3.4 |
| 18 | 4.9 |
| 20 | 6.7 |
| 22 | 8.9 |
| 24 | 11.5 |
| 26 | 14.6 |
| 28 | 18.3 |
| 30 | 22.5 |
Estimating weight without a scale
Length-to-weight formulas like the one above assume a typical largemouth bass shape for a given length - fisheries biologists call this the cube law. Real fish vary: a well-fed fish ahead of spawning season can weigh noticeably more than a lean fish of the same length, and body shape varies fish to fish.
Adding girth (the distance around the fish at its widest point) meaningfully improves the estimate, because it captures how deep-bodied this particular fish actually is instead of assuming average proportions for the species - use the calculator above and fill in girth if you can measure it.
Either way, treat the result as a solid estimate, not a certified weight - see our terms for why these numbers shouldn't be used for tournaments, regulations, or sales.